diff --git a/app/assets/javascripts/app/controllers/ticket_zoom/meta.coffee b/app/assets/javascripts/app/controllers/ticket_zoom/meta.coffee
index a5cab432e..ed2aa0228 100644
--- a/app/assets/javascripts/app/controllers/ticket_zoom/meta.coffee
+++ b/app/assets/javascripts/app/controllers/ticket_zoom/meta.coffee
@@ -3,7 +3,7 @@ class App.TicketZoomMeta extends App.ObserverController
   observe:
     number: true
     created_at: true
-    escalation_time: true
+    escalation_at: true
 
   render: (ticket) =>
     @html App.view('ticket_zoom/meta')(
diff --git a/app/assets/javascripts/app/models/overview.coffee b/app/assets/javascripts/app/models/overview.coffee
index a5b3010b4..7e94633a2 100644
--- a/app/assets/javascripts/app/models/overview.coffee
+++ b/app/assets/javascripts/app/models/overview.coffee
@@ -47,23 +47,23 @@ class App.Overview extends App.Model
           name:   'Owner'
         },
         {
-          value:  'last_contact'
+          value:  'last_contact_at'
           name:   'Last contact'
         },
         {
-          value:  'last_contact_agent'
+          value:  'last_contact_agent_at'
           name:   'Last contact (Agent)'
         },
         {
-          value:  'last_contact_customer'
+          value:  'last_contact_customer_at'
           name:   'Last contact (Customer)'
         },
         {
-          value:  'first_response'
+          value:  'first_response_at'
           name:   'First Response'
         },
         {
-          value:  'close_time'
+          value:  'close_at'
           name:   'Close time'
         },
         {
@@ -90,21 +90,21 @@ class App.Overview extends App.Model
       null:    false
       translate: true
       options:
-        number:                 'Number'
-        title:                  'Title'
-        customer:               'Customer'
-        state:                  'State'
-        priority:               'Priority'
-        group:                  'Group'
-        owner:                  'Owner'
-        last_contact:           'Last contact'
-        last_contact_agent:     'Last contact (Agent)'
-        last_contact_customer:  'Last contact (Customer)'
-        first_response:         'First Response'
-        close_time:             'Close time'
-        article_count:          'Article Count'
-        updated_at:             'Updated at'
-        created_at:             'Created at'
+        number:                   'Number'
+        title:                    'Title'
+        customer:                 'Customer'
+        state:                    'State'
+        priority:                 'Priority'
+        group:                    'Group'
+        owner:                    'Owner'
+        last_contact_at:          'Last contact'
+        last_contact_agent_at:    'Last contact (Agent)'
+        last_contact_customer_at: 'Last contact (Customer)'
+        first_response_at:        'First Response'
+        close_at:                 'Close time'
+        article_count:            'Article Count'
+        updated_at:               'Updated at'
+        created_at:               'Created at'
       class:   'span4'
     },
     {
diff --git a/app/assets/javascripts/app/models/ticket.coffee b/app/assets/javascripts/app/models/ticket.coffee
index a037ff143..124c134e8 100644
--- a/app/assets/javascripts/app/models/ticket.coffee
+++ b/app/assets/javascripts/app/models/ticket.coffee
@@ -3,46 +3,46 @@ class App.Ticket extends App.Model
   @extend Spine.Model.Ajax
   @url: @apiPath + '/tickets'
   @configure_attributes = [
-      { name: 'number',                display: '#',            tag: 'input',    type: 'text', limit: 100, null: true, readonly: 1, width: '68px' },
-      { name: 'title',                 display: 'Title',        tag: 'input',    type: 'text', limit: 100, null: false },
-      { name: 'customer_id',           display: 'Customer',     tag: 'input',    type: 'text', limit: 100, null: false, autocapitalize: false, relation: 'User' },
-      { name: 'organization_id',       display: 'Organization', tag: 'select',   relation: 'Organization', readonly: 1 },
-      { name: 'group_id',              display: 'Group',        tag: 'select',   multiple: false, limit: 100, null: false, relation: 'Group', width: '10%', edit: true },
-      { name: 'owner_id',              display: 'Owner',        tag: 'select',   multiple: false, limit: 100, null: true, relation: 'User', width: '12%', edit: true },
-      { name: 'state_id',              display: 'State',        tag: 'select',   multiple: false, null: false, relation: 'TicketState', default: 'new', width: '12%', edit: true, customer: true },
-      { name: 'pending_time',          display: 'Pending Time', tag: 'datetime', null: true, width: '130px' },
-      { name: 'priority_id',           display: 'Priority',     tag: 'select',   multiple: false, null: false, relation: 'TicketPriority', default: '2 normal', width: '12%', edit: true, customer: true },
-      { name: 'article_count',         display: 'Article#',     readonly: 1, width: '12%' },
-      { name: 'escalation_time',       display: 'Escalation',              tag: 'datetime', null: true, readonly: 1, width: '110px', class: 'escalation' },
-      { name: 'last_contact',          display: 'Last contact',            tag: 'datetime', null: true, readonly: 1, width: '110px' },
-      { name: 'last_contact_agent',    display: 'Last contact (Agent)',    tag: 'datetime', null: true, readonly: 1, width: '110px' },
-      { name: 'last_contact_customer', display: 'Last contact (Customer)', tag: 'datetime', null: true, readonly: 1, width: '110px' },
-      { name: 'first_response',        display: 'First response',          tag: 'datetime', null: true, readonly: 1, width: '110px' },
-      { name: 'close_time',            display: 'Close time',              tag: 'datetime', null: true, readonly: 1, width: '110px' },
-      { name: 'created_by_id',         display: 'Created by',   relation: 'User', readonly: 1 },
-      { name: 'created_at',            display: 'Created at',   tag: 'datetime', width: '110px', align: 'right', readonly: 1 },
-      { name: 'updated_by_id',         display: 'Updated by',   relation: 'User', readonly: 1 },
-      { name: 'updated_at',            display: 'Updated at',   tag: 'datetime', width: '110px', align: 'right', readonly: 1 },
+      { name: 'number',                   display: '#',            tag: 'input',    type: 'text', limit: 100, null: true, readonly: 1, width: '68px' },
+      { name: 'title',                    display: 'Title',        tag: 'input',    type: 'text', limit: 100, null: false },
+      { name: 'customer_id',              display: 'Customer',     tag: 'input',    type: 'text', limit: 100, null: false, autocapitalize: false, relation: 'User' },
+      { name: 'organization_id',          display: 'Organization', tag: 'select',   relation: 'Organization', readonly: 1 },
+      { name: 'group_id',                 display: 'Group',        tag: 'select',   multiple: false, limit: 100, null: false, relation: 'Group', width: '10%', edit: true },
+      { name: 'owner_id',                 display: 'Owner',        tag: 'select',   multiple: false, limit: 100, null: true, relation: 'User', width: '12%', edit: true },
+      { name: 'state_id',                 display: 'State',        tag: 'select',   multiple: false, null: false, relation: 'TicketState', default: 'new', width: '12%', edit: true, customer: true },
+      { name: 'pending_time',             display: 'Pending Time', tag: 'datetime', null: true, width: '130px' },
+      { name: 'priority_id',              display: 'Priority',     tag: 'select',   multiple: false, null: false, relation: 'TicketPriority', default: '2 normal', width: '12%', edit: true, customer: true },
+      { name: 'article_count',            display: 'Article#',     readonly: 1, width: '12%' },
+      { name: 'escalation_at',            display: 'Escalation',              tag: 'datetime', null: true, readonly: 1, width: '110px', class: 'escalation' },
+      { name: 'last_contact_at',          display: 'Last contact',            tag: 'datetime', null: true, readonly: 1, width: '110px' },
+      { name: 'last_contact_agent_at',    display: 'Last contact (Agent)',    tag: 'datetime', null: true, readonly: 1, width: '110px' },
+      { name: 'last_contact_customer_at', display: 'Last contact (Customer)', tag: 'datetime', null: true, readonly: 1, width: '110px' },
+      { name: 'first_response_at',        display: 'First response',          tag: 'datetime', null: true, readonly: 1, width: '110px' },
+      { name: 'close_at',                 display: 'Close time',              tag: 'datetime', null: true, readonly: 1, width: '110px' },
+      { name: 'created_by_id',            display: 'Created by',   relation: 'User', readonly: 1 },
+      { name: 'created_at',               display: 'Created at',   tag: 'datetime', width: '110px', align: 'right', readonly: 1 },
+      { name: 'updated_by_id',            display: 'Updated by',   relation: 'User', readonly: 1 },
+      { name: 'updated_at',               display: 'Updated at',   tag: 'datetime', width: '110px', align: 'right', readonly: 1 },
     ]
 
   uiUrl: ->
     '#ticket/zoom/' + @id
 
   getState: ->
-    type = App.TicketState.find( @state_id )
-    stateType = App.TicketStateType.find( type.state_type_id )
+    type = App.TicketState.find(@state_id)
+    stateType = App.TicketStateType.find(type.state_type_id)
     state = 'closed'
     if stateType.name is 'new' || stateType.name is 'open'
       state = 'open'
 
       # if ticket is escalated, overwrite state
-      if @escalation_time && new Date( Date.parse( @escalation_time ) ) < new Date
+      if @escalation_at && new Date( Date.parse(@escalation_at) ) < new Date
         state = 'escalating'
     else if stateType.name is 'pending reminder'
       state = 'pending'
 
       # if ticket pending_time is reached, overwrite state
-      if @pending_time && new Date( Date.parse( @pending_time ) ) < new Date
+      if @pending_time && new Date( Date.parse(@pending_time) ) < new Date
         state = 'open'
     else if stateType.name is 'pending action'
       state = 'pending'
@@ -55,11 +55,11 @@ class App.Ticket extends App.Model
     @getState()
 
   iconTitle: ->
-    type = App.TicketState.find( @state_id )
-    stateType = App.TicketStateType.find( type.state_type_id )
-    if stateType.name is 'pending reminder' && @pending_time && new Date( Date.parse( @pending_time ) ) < new Date
+    type = App.TicketState.find(@state_id)
+    stateType = App.TicketStateType.find(type.state_type_id)
+    if stateType.name is 'pending reminder' && @pending_time && new Date( Date.parse(@pending_time) ) < new Date
       return "#{App.i18n.translateInline(type.displayName())} - #{App.i18n.translateInline('reached')}"
-    if @escalation_time && new Date( Date.parse( @escalation_time ) ) < new Date
+    if @escalation_at && new Date( Date.parse(@escalation_at) ) < new Date
       return "#{App.i18n.translateInline(type.displayName())} - #{App.i18n.translateInline('escalated')}"
     App.i18n.translateInline(type.displayName())
 
diff --git a/app/assets/javascripts/app/views/ticket_zoom/meta.jst.eco b/app/assets/javascripts/app/views/ticket_zoom/meta.jst.eco
index 5f1130a17..8b5eea7cb 100644
--- a/app/assets/javascripts/app/views/ticket_zoom/meta.jst.eco
+++ b/app/assets/javascripts/app/views/ticket_zoom/meta.jst.eco
@@ -1,3 +1,3 @@
 <small class="task-subline">
-  <%- @C('ticket_hook') %> <span class="ticket-number js-objectNumber" data-number="<%- @C('ticket_hook') %><%- @ticket.number %>"><%- @ticket.number %></span> - <%- @T('created') %> <%- @humanTime(@ticket.created_at) %> <% if !@isCustomer && @ticket.escalation_time: %> - <%- @T('escalation') %> <%- @humanTime(@ticket.escalation_time, true) %><% end %>
+  <%- @C('ticket_hook') %> <span class="ticket-number js-objectNumber" data-number="<%- @C('ticket_hook') %><%- @ticket.number %>"><%- @ticket.number %></span> - <%- @T('created') %> <%- @humanTime(@ticket.created_at) %> <% if !@isCustomer && @ticket.escalation_at: %> - <%- @T('escalation') %> <%- @humanTime(@ticket.escalation_at, true) %><% end %>
 </small>
\ No newline at end of file
diff --git a/app/controllers/reports_controller.rb b/app/controllers/reports_controller.rb
index 122abd177..ec3f53567 100644
--- a/app/controllers/reports_controller.rb
+++ b/app/controllers/reports_controller.rb
@@ -37,7 +37,7 @@ class ReportsController < ApplicationController
     }
 
     #created = aggs(start, stop, range, 'created_at', profile.condition)
-    #closed = aggs(start, stop, range, 'close_time', profile.condition)
+    #closed = aggs(start, stop, range, 'close_at', profile.condition)
     #first_solution =
     #reopend = backend(start, stop, range, Report::TicketReopened, profile.condition)
 
@@ -208,7 +208,7 @@ class ReportsController < ApplicationController
       worksheet.write(row, 4, ticket.customer.fullname)
       worksheet.write(row, 5, ticket.created_at)
       worksheet.write(row, 6, ticket.updated_at)
-      worksheet.write(row, 7, ticket.close_time)
+      worksheet.write(row, 7, ticket.close_at)
     }
 
     workbook.close
diff --git a/app/controllers/tickets_controller.rb b/app/controllers/tickets_controller.rb
index f78926e98..3056c37fd 100644
--- a/app/controllers/tickets_controller.rb
+++ b/app/controllers/tickets_controller.rb
@@ -543,7 +543,7 @@ class TicketsController < ApplicationController
                         .count
 
         # closed
-        closed = Ticket.where('close_time > ? AND close_time < ?', date_start, date_end  )
+        closed = Ticket.where('close_at > ? AND close_at < ?', date_start, date_end  )
                        .where(access_condition)
                        .where(condition)
                        .count
@@ -614,7 +614,7 @@ class TicketsController < ApplicationController
         created = Ticket.where('created_at > ? AND created_at < ?', date_start, date_end ).where(condition).count
 
         # closed
-        closed = Ticket.where('close_time > ? AND close_time < ?', date_start, date_end  ).where(condition).count
+        closed = Ticket.where('close_at > ? AND close_at < ?', date_start, date_end  ).where(condition).count
 
         data = {
           month: date_to_check.month,
diff --git a/app/models/observer/ticket/article_changes.rb b/app/models/observer/ticket/article_changes.rb
index 938853e08..1d75b8927 100644
--- a/app/models/observer/ticket/article_changes.rb
+++ b/app/models/observer/ticket/article_changes.rb
@@ -10,7 +10,7 @@ class Observer::Ticket::ArticleChanges < ActiveRecord::Observer
       changed = true
     end
 
-    if first_response_update(record)
+    if first_response_at_update(record)
       changed = true
     end
 
@@ -18,7 +18,7 @@ class Observer::Ticket::ArticleChanges < ActiveRecord::Observer
       changed = true
     end
 
-    if last_contact_update(record)
+    if last_contact_update_at(record)
       changed = true
     end
 
@@ -41,7 +41,7 @@ class Observer::Ticket::ArticleChanges < ActiveRecord::Observer
   end
 
   # set frist response
-  def first_response_update(record)
+  def first_response_at_update(record)
 
     # return if we run import mode
     return false if Setting.get('import_mode')
@@ -57,11 +57,11 @@ class Observer::Ticket::ArticleChanges < ActiveRecord::Observer
     type = Ticket::Article::Type.lookup(id: record.type_id)
     return false if !type.communication
 
-    # check if first_response is already set
-    return false if record.ticket.first_response
+    # check if first_response_at is already set
+    return false if record.ticket.first_response_at
 
-    # set first_response
-    record.ticket.first_response = record.created_at
+    # set first_response_at
+    record.ticket.first_response_at = record.created_at
 
     true
   end
@@ -79,7 +79,7 @@ class Observer::Ticket::ArticleChanges < ActiveRecord::Observer
   end
 
   # set last contact
-  def last_contact_update(record)
+  def last_contact_update_at(record)
 
     # if article in internal
     return false if record.internal
@@ -97,20 +97,20 @@ class Observer::Ticket::ArticleChanges < ActiveRecord::Observer
     if sender.name == 'Customer'
 
       # if customer is sending agains, ignore update of last contact (usecase of update escalation)
-      return false if ticket.last_contact_customer &&
-                      ticket.last_contact &&
-                      ticket.last_contact_customer == ticket.last_contact
+      return false if ticket.last_contact_customer_at &&
+                      ticket.last_contact_at &&
+                      ticket.last_contact_customer_at == ticket.last_contact_at
 
-      # check if last communication is done by agent, else do not set last_contact_customer
-      if ticket.last_contact_customer.nil? ||
-         ticket.last_contact_agent.nil? ||
-         ticket.last_contact_agent.to_i > ticket.last_contact_customer.to_i
+      # check if last communication is done by agent, else do not set last_contact_customer_at
+      if ticket.last_contact_customer_at.nil? ||
+         ticket.last_contact_agent_at.nil? ||
+         ticket.last_contact_agent_at.to_i > ticket.last_contact_customer_at.to_i
 
-        # set last_contact customer
-        record.ticket.last_contact_customer = record.created_at
+        # set last_contact_at customer
+        record.ticket.last_contact_customer_at = record.created_at
 
         # set last_contact
-        record.ticket.last_contact = record.created_at
+        record.ticket.last_contact_at = record.created_at
 
       end
       return true
@@ -119,11 +119,11 @@ class Observer::Ticket::ArticleChanges < ActiveRecord::Observer
     # if sender is not agent
     return false if sender.name != 'Agent'
 
-    # set last_contact_agent
-    record.ticket.last_contact_agent = record.created_at
+    # set last_contact_agent_at
+    record.ticket.last_contact_agent_at = record.created_at
 
     # set last_contact
-    record.ticket.last_contact = record.created_at
+    record.ticket.last_contact_at = record.created_at
 
     true
   end
diff --git a/app/models/observer/ticket/close_time.rb b/app/models/observer/ticket/close_time.rb
index 2c5d0b4b3..80f2947cd 100644
--- a/app/models/observer/ticket/close_time.rb
+++ b/app/models/observer/ticket/close_time.rb
@@ -18,8 +18,8 @@ class Observer::Ticket::CloseTime < ActiveRecord::Observer
     # return if we run import mode
     return if Setting.get('import_mode')
 
-    # check if close_time is already set
-    return true if record.close_time
+    # check if close_at is already set
+    return true if record.close_at
 
     # check if ticket is closed now
     return if !record.state_id
@@ -27,7 +27,7 @@ class Observer::Ticket::CloseTime < ActiveRecord::Observer
     state_type = Ticket::StateType.lookup(id: state.state_type_id)
     return true if state_type.name != 'closed'
 
-    # set close_time
-    record.close_time = Time.zone.now
+    # set close_at
+    record.close_at = Time.zone.now
   end
 end
diff --git a/app/models/observer/transaction.rb b/app/models/observer/transaction.rb
index aaeb36fec..f8972494b 100644
--- a/app/models/observer/transaction.rb
+++ b/app/models/observer/transaction.rb
@@ -196,11 +196,11 @@ class Observer::Transaction < ActiveRecord::Observer
     real_changes = {}
     record.changes.each { |key, value|
       next if key == 'updated_at'
-      next if key == 'first_response'
-      next if key == 'close_time'
-      next if key == 'last_contact_agent'
-      next if key == 'last_contact_customer'
-      next if key == 'last_contact'
+      next if key == 'first_response_at'
+      next if key == 'close_at'
+      next if key == 'last_contact_agent_at'
+      next if key == 'last_contact_customer_at'
+      next if key == 'last_contact_at'
       next if key == 'article_count'
       next if key == 'create_article_type_id'
       next if key == 'create_article_sender_id'
diff --git a/app/models/report.rb b/app/models/report.rb
index 03e75bc41..e754779b8 100644
--- a/app/models/report.rb
+++ b/app/models/report.rb
@@ -25,7 +25,7 @@ class Report
         selected: true,
         dataDownload: true,
         adapter: Report::TicketGenericTime,
-        params: { field: 'close_time' },
+        params: { field: 'close_at' },
       },
       {
         name: 'backlog',
diff --git a/app/models/ticket.rb b/app/models/ticket.rb
index fd1b1fa2d..73c72a71b 100644
--- a/app/models/ticket.rb
+++ b/app/models/ticket.rb
@@ -35,23 +35,20 @@ class Ticket < ApplicationModel
       create_article_type_id: true,
       create_article_sender_id: true,
       article_count: true,
-      first_response: true,
-      first_response_escal_date: true,
-      first_response_sla_time: true,
+      first_response_at: true,
+      first_response_escalation_at: true,
       first_response_in_min: true,
       first_response_diff_in_min: true,
-      close_time: true,
-      close_time_escal_date: true,
-      close_time_sla_time: true,
-      close_time_in_min: true,
-      close_time_diff_in_min: true,
-      update_time_escal_date: true,
-      update_time_sla_time: true,
-      update_time_in_min: true,
-      update_time_diff_in_min: true,
-      last_contact: true,
-      last_contact_agent: true,
-      last_contact_customer: true,
+      close_at: true,
+      close_escalation_at: true,
+      close_in_min: true,
+      close_diff_in_min: true,
+      update_escalation_at: true,
+      update_in_min: true,
+      update_diff_in_min: true,
+      last_contact_at: true,
+      last_contact_agent_at: true,
+      last_contact_customer_at: true,
     }
   )
 
@@ -228,7 +225,7 @@ returns
 
     # get max warning diff
 
-    tickets = where('escalation_time <= ?', Time.zone.now + 15.minutes)
+    tickets = where('escalation_at <= ?', Time.zone.now + 15.minutes)
 
     tickets.each { |ticket|
 
@@ -242,7 +239,7 @@ returns
       end
 
       # send escalation
-      if ticket.escalation_time < Time.zone.now
+      if ticket.escalation_at < Time.zone.now
         Transaction::BackgroundJob.run(
           object: 'Ticket',
           type: 'escalation',
@@ -447,7 +444,7 @@ condition example
       pre_condition: 'specific',
       value: 4711,
     },
-    'ticket.escalation_time' => {
+    'ticket.escalation_at' => {
       operator: 'is not', # not
       value: nil,
     }
diff --git a/app/models/ticket/escalation.rb b/app/models/ticket/escalation.rb
index 8853e4c45..8900e4512 100644
--- a/app/models/ticket/escalation.rb
+++ b/app/models/ticket/escalation.rb
@@ -58,8 +58,8 @@ returns
 
       # early exit if nothing current state is not escalation relativ
       if !force
-        return false if escalation_time.nil?
-        self.escalation_time = nil
+        return false if escalation_at.nil?
+        self.escalation_at = nil
         return true
       end
     end
@@ -76,22 +76,22 @@ returns
       preferences[:escalation_calculation] = {}
 
       # nothing to change
-      return false if !escalation_time
-      self.escalation_time = nil
+      return false if !escalation_at
+      self.escalation_at = nil
       return true
     end
 
-    # get last_update
-    if !last_contact_customer && !last_contact_agent
-      last_update = created_at
-    elsif !last_contact_customer && last_contact_agent
-      last_update = last_contact_agent
-    elsif last_contact_customer && !last_contact_agent
-      last_update = last_contact_customer
-    elsif last_contact_agent > last_contact_customer
-      last_update = last_contact_agent
-    elsif last_contact_agent < last_contact_customer
-      last_update = last_contact_customer
+    # get last_update_at
+    if !last_contact_customer_at && !last_contact_agent_at
+      last_update_at = created_at
+    elsif !last_contact_customer_at && last_contact_agent_at
+      last_update_at = last_contact_agent_at
+    elsif last_contact_customer_at && !last_contact_agent_at
+      last_update_at = last_contact_customer_at
+    elsif last_contact_agent_at > last_contact_customer_at
+      last_update_at = last_contact_agent_at
+    elsif last_contact_agent_at < last_contact_customer_at
+      last_update_at = last_contact_customer_at
     end
 
     # check if calculation need be done
@@ -107,23 +107,23 @@ returns
     if sla_changed == true || calendar_changed == true
       force = true
     end
-    first_response_changed = true
-    if escalation_calculation['first_response'] == first_response
-      first_response_changed = false
+    first_response_at_changed = true
+    if escalation_calculation['first_response_at'] == first_response_at
+      first_response_at_changed = false
     end
-    last_update_changed = true
-    if escalation_calculation['last_update'] == last_update
-      last_update_changed = false
+    last_update_at_changed = true
+    if escalation_calculation['last_update_at'] == last_update_at
+      last_update_at_changed = false
     end
-    close_time_changed = true
-    if escalation_calculation['close_time'] == close_time
-      close_time_changed = false
+    close_at_changed = true
+    if escalation_calculation['close_at'] == close_at
+      close_at_changed = false
     end
 
     if !force && preferences[:escalation_calculation]
-      if first_response_changed == false &&
-         last_update_changed == false &&
-         close_time_changed == false &&
+      if first_response_at_changed == false &&
+         last_update_at_changed == false &&
+         close_at_changed == false &&
          sla_changed == false &&
          calendar_changed == false &&
          escalation_calculation['escalation_disabled'] == escalation_disabled
@@ -132,11 +132,11 @@ returns
     end
 
     # reset escalation attributes
-    self.escalation_time = nil
+    self.escalation_at = nil
     if force == true
-      self.first_response_escal_date = nil
-      self.update_time_escal_date    = nil
-      self.close_time_escal_date     = nil
+      self.first_response_escalation_at = nil
+      self.update_escalation_at    = nil
+      self.close_escalation_at     = nil
     end
     biz = Biz::Schedule.new do |config|
 
@@ -175,17 +175,17 @@ returns
     history_data = nil
 
     # calculate first response escalation
-    if force == true || first_response_changed == true
+    if force == true || first_response_at_changed == true
       if !history_data
         history_data = history_get
       end
       if sla.first_response_time
-        self.first_response_escal_date = destination_time(created_at, sla.first_response_time, biz, history_data)
+        self.first_response_escalation_at = destination_time(created_at, sla.first_response_time, biz, history_data)
       end
 
       # get response time in min
-      if first_response
-        self.first_response_in_min = pending_minutes(created_at, first_response, biz, history_data, 'business_minutes')
+      if first_response_at
+        self.first_response_in_min = pending_minutes(created_at, first_response_at, biz, history_data, 'business_minutes')
       end
 
       # set time to show if sla is raised or not
@@ -195,65 +195,65 @@ returns
     end
 
     # calculate update time escalation
-    if force == true || last_update_changed == true
+    if force == true || last_update_at_changed == true
       if !history_data
         history_data = history_get
       end
-      if sla.update_time && last_update
-        self.update_time_escal_date = destination_time(last_update, sla.update_time, biz, history_data)
+      if sla.update_time && last_update_at
+        self.update_escalation_at = destination_time(last_update_at, sla.update_time, biz, history_data)
       end
 
       # get update time in min
-      if last_update && last_update != created_at
-        self.update_time_in_min = pending_minutes(created_at, last_update, biz, history_data, 'business_minutes')
+      if last_update_at && last_update_at != created_at
+        self.update_in_min = pending_minutes(created_at, last_update_at, biz, history_data, 'business_minutes')
       end
 
       # set sla time
-      if sla.update_time && update_time_in_min
-        self.update_time_diff_in_min = sla.update_time - update_time_in_min
+      if sla.update_time && update_in_min
+        self.update_diff_in_min = sla.update_time - update_in_min
       end
     end
 
     # calculate close time escalation
-    if force == true || close_time_changed == true
+    if force == true || close_at_changed == true
       if !history_data
         history_data = history_get
       end
       if sla.solution_time
-        self.close_time_escal_date = destination_time(created_at, sla.solution_time, biz, history_data)
+        self.close_escalation_at = destination_time(created_at, sla.solution_time, biz, history_data)
       end
 
       # get close time in min
-      if close_time
-        self.close_time_in_min = pending_minutes(created_at, close_time, biz, history_data, 'business_minutes')
+      if close_at
+        self.close_in_min = pending_minutes(created_at, close_at, biz, history_data, 'business_minutes')
       end
 
       # set time to show if sla is raised or not
-      if sla.solution_time && close_time_in_min
-        self.close_time_diff_in_min = sla.solution_time - close_time_in_min
+      if sla.solution_time && close_in_min
+        self.close_diff_in_min = sla.solution_time - close_in_min
       end
     end
 
     # set closest escalation time
     if escalation_disabled
-      self.escalation_time = nil
+      self.escalation_at = nil
     else
-      if !first_response && first_response_escal_date
-        self.escalation_time = first_response_escal_date
+      if !first_response_at && first_response_escalation_at
+        self.escalation_at = first_response_escalation_at
       end
-      if update_time_escal_date && ((!escalation_time && update_time_escal_date) || update_time_escal_date < escalation_time)
-        self.escalation_time = update_time_escal_date
+      if update_escalation_at && ((!escalation_at && update_escalation_at) || update_escalation_at < escalation_at)
+        self.escalation_at = update_escalation_at
       end
-      if !close_time && close_time_escal_date && ((!escalation_time && close_time_escal_date) || close_time_escal_date < escalation_time)
-        self.escalation_time = close_time_escal_date
+      if !close_at && close_escalation_at && ((!escalation_at && close_escalation_at) || close_escalation_at < escalation_at)
+        self.escalation_at = close_escalation_at
       end
     end
 
     # remember already counted time to do on next update only the diff
     preferences[:escalation_calculation] = {
-      first_response: first_response,
-      last_update: last_update,
-      close_time: close_time,
+      first_response_at: first_response_at,
+      last_update_at: last_update_at,
+      close_at: close_at,
       sla_id: sla.id,
       sla_updated_at: sla.updated_at,
       calendar_id: calendar.id,
diff --git a/app/models/transaction/slack.rb b/app/models/transaction/slack.rb
index bf4b630b1..963575347 100644
--- a/app/models/transaction/slack.rb
+++ b/app/models/transaction/slack.rb
@@ -66,10 +66,10 @@ class Transaction::Slack
       sent_value = ticket.pending_time
     elsif @item[:type] == 'escalation'
       template = 'ticket_escalation'
-      sent_value = ticket.escalation_time
+      sent_value = ticket.escalation_at
     elsif @item[:type] == 'escalation_warning'
       template = 'ticket_escalation_warning'
-      sent_value = ticket.escalation_time
+      sent_value = ticket.escalation_at
     else
       raise "unknown type for notification #{@item[:type]}"
     end
@@ -95,7 +95,7 @@ class Transaction::Slack
     # good, warning, danger
     color = '#000000'
     ticket_state_type = ticket.state.state_type.name
-    if ticket.escalation_time && ticket.escalation_time < Time.zone.now
+    if ticket.escalation_at && ticket.escalation_at < Time.zone.now
       color = '#f35912'
     elsif ticket_state_type == 'pending reminder'
       if ticket.pending_time && ticket.pending_time < Time.zone.now
diff --git a/app/views/mailer/ticket_escalation/de.html.erb b/app/views/mailer/ticket_escalation/de.html.erb
index 24137ff57..86ba3da5d 100644
--- a/app/views/mailer/ticket_escalation/de.html.erb
+++ b/app/views/mailer/ticket_escalation/de.html.erb
@@ -2,7 +2,7 @@ Ticket ist eskaliert (<%= d 'ticket.title' %>)
 
 <div>Hallo <%= d 'recipient.firstname' %>,</div>
 <br>
-<div>Ticket (<%= d 'ticket.title' %>) von "<b><%= d 'ticket.customer.longname' %></b>" ist seit "<%= d 'ticket.escalation_time' %>" eskaliert!</div>
+<div>Ticket (<%= d 'ticket.title' %>) von "<b><%= d 'ticket.customer.longname' %></b>" ist seit "<%= d 'ticket.escalation_at' %>" eskaliert!</div>
 <br>
 <% if @objects[:article] %>
   <div>
diff --git a/app/views/mailer/ticket_escalation/en.html.erb b/app/views/mailer/ticket_escalation/en.html.erb
index a835ffb94..078a55262 100644
--- a/app/views/mailer/ticket_escalation/en.html.erb
+++ b/app/views/mailer/ticket_escalation/en.html.erb
@@ -2,7 +2,7 @@ Ticket is escalated (<%= d 'ticket.title' %>)
 
 <div>Hi <%= d 'recipient.firstname' %>,</div>
 <br>
-<div>A ticket (<%= d 'ticket.title' %>) from "<b><%= d 'ticket.customer.longname' %></b>" is escalated since "<%= d 'ticket.escalation_time' %>"!</div>
+<div>A ticket (<%= d 'ticket.title' %>) from "<b><%= d 'ticket.customer.longname' %></b>" is escalated since "<%= d 'ticket.escalation_at' %>"!</div>
 <br>
 <% if @objects[:article] %>
   <div>
diff --git a/app/views/mailer/ticket_escalation_warning/de.html.erb b/app/views/mailer/ticket_escalation_warning/de.html.erb
index 9f1e64658..d78d8fe48 100644
--- a/app/views/mailer/ticket_escalation_warning/de.html.erb
+++ b/app/views/mailer/ticket_escalation_warning/de.html.erb
@@ -2,7 +2,7 @@ Ticket wird eskalieren (<%= d 'ticket.title' %>)
 
 <div>Hallo <%= d 'recipient.firstname' %>,</div>
 <br>
-<div>Ticket (<%= d 'ticket.title' %>) von "<b><%= d 'ticket.customer.longname' %></b>" wird um "<%= d 'ticket.escalation_time' %>" eskalieren!</div>
+<div>Ticket (<%= d 'ticket.title' %>) von "<b><%= d 'ticket.customer.longname' %></b>" wird um "<%= d 'ticket.escalation_at' %>" eskalieren!</div>
 <br>
 <% if @objects[:article] %>
   <div>
diff --git a/app/views/mailer/ticket_escalation_warning/en.html.erb b/app/views/mailer/ticket_escalation_warning/en.html.erb
index 6742ff422..0952efc91 100644
--- a/app/views/mailer/ticket_escalation_warning/en.html.erb
+++ b/app/views/mailer/ticket_escalation_warning/en.html.erb
@@ -2,7 +2,7 @@ Ticket will escalate (<%= d 'ticket.title' %>)
 
 <div>Hi <%= d 'recipient.firstname' %>,</div>
 <br>
-<div>A ticket (<%= d 'ticket.title' %>) from "<b><%= d 'ticket.customer.longname' %></b>" will escalate at "<%= d 'ticket.escalation_time' %>"!</div>
+<div>A ticket (<%= d 'ticket.title' %>) from "<b><%= d 'ticket.customer.longname' %></b>" will escalate at "<%= d 'ticket.escalation_at' %>"!</div>
 <br>
 <% if @objects[:article] %>
   <div>
diff --git a/app/views/slack/ticket_escalation/en.md.erb b/app/views/slack/ticket_escalation/en.md.erb
index e4853da66..e9d232544 100644
--- a/app/views/slack/ticket_escalation/en.md.erb
+++ b/app/views/slack/ticket_escalation/en.md.erb
@@ -1,6 +1,6 @@
 # <%= d 'ticket.title' %>
-_<<%= c 'http_type' %>://<%= c 'fqdn' %>/#ticket/zoom/<%= d 'ticket.id' %>|Ticket#<%= d 'ticket.number' %>>: Escalated at <%= d 'ticket.escalation_time' %>_
-A ticket (<%= d 'ticket.title' %>) from "<%= d 'ticket.customer.longname' %>" is escalated since "<%= d 'ticket.escalation_time' %>"!
+_<<%= c 'http_type' %>://<%= c 'fqdn' %>/#ticket/zoom/<%= d 'ticket.id' %>|Ticket#<%= d 'ticket.number' %>>: Escalated at <%= d 'ticket.escalation_at' %>_
+A ticket (<%= d 'ticket.title' %>) from "<%= d 'ticket.customer.longname' %>" is escalated since "<%= d 'ticket.escalation_at' %>"!
 
 <% if @objects[:article] %>
 <%= a_text 'article' %>
diff --git a/app/views/slack/ticket_escalation_warning/en.md.erb b/app/views/slack/ticket_escalation_warning/en.md.erb
index 806c49fba..15068b0fb 100644
--- a/app/views/slack/ticket_escalation_warning/en.md.erb
+++ b/app/views/slack/ticket_escalation_warning/en.md.erb
@@ -1,6 +1,6 @@
 # <%= d 'ticket.title' %>
-_<<%= c 'http_type' %>://<%= c 'fqdn' %>/#ticket/zoom/<%= d 'ticket.id' %>|Ticket#<%= d 'ticket.number' %>>: Will escalate at <%= d 'ticket.escalation_time' %>_
-A ticket (<%= d 'ticket.title' %>) from "<%= d 'ticket.customer.longname' %>" will escalate at "<%= d 'ticket.escalation_time' %>"!
+_<<%= c 'http_type' %>://<%= c 'fqdn' %>/#ticket/zoom/<%= d 'ticket.id' %>|Ticket#<%= d 'ticket.number' %>>: Will escalate at <%= d 'ticket.escalation_at' %>_
+A ticket (<%= d 'ticket.title' %>) from "<%= d 'ticket.customer.longname' %>" will escalate at "<%= d 'ticket.escalation_at' %>"!
 
 <% if @objects[:article] %>
 <%= a_text 'article' %>
diff --git a/db/migrate/20120101000010_create_ticket.rb b/db/migrate/20120101000010_create_ticket.rb
index 4a2acc4fa..40dcc06a5 100644
--- a/db/migrate/20120101000010_create_ticket.rb
+++ b/db/migrate/20120101000010_create_ticket.rb
@@ -41,27 +41,24 @@ class CreateTicket < ActiveRecord::Migration
       t.column :owner_id,                         :integer,               null: false
       t.column :customer_id,                      :integer,               null: false
       t.column :note,                             :string,    limit: 250, null: true
-      t.column :first_response,                   :timestamp, limit: 3,   null: true
-      t.column :first_response_escal_date,        :timestamp, limit: 3,   null: true
-      t.column :first_response_sla_time,          :timestamp, limit: 3,   null: true
+      t.column :first_response_at,                :timestamp, limit: 3,   null: true
+      t.column :first_response_escalation_at,     :timestamp, limit: 3,   null: true
       t.column :first_response_in_min,            :integer,               null: true
       t.column :first_response_diff_in_min,       :integer,               null: true
-      t.column :close_time,                       :timestamp, limit: 3,   null: true
-      t.column :close_time_escal_date,            :timestamp, limit: 3,   null: true
-      t.column :close_time_sla_time,              :timestamp, limit: 3,   null: true
-      t.column :close_time_in_min,                :integer,               null: true
-      t.column :close_time_diff_in_min,           :integer,               null: true
-      t.column :update_time_escal_date,           :timestamp, limit: 3,   null: true
-      t.column :update_time_sla_time,             :timestamp, limit: 3,   null: true
-      t.column :update_time_in_min,               :integer,               null: true
-      t.column :update_time_diff_in_min,          :integer,               null: true
-      t.column :last_contact,                     :timestamp, limit: 3,   null: true
-      t.column :last_contact_agent,               :timestamp, limit: 3,   null: true
-      t.column :last_contact_customer,            :timestamp, limit: 3,   null: true
+      t.column :close_at,                         :timestamp, limit: 3,   null: true
+      t.column :close_escalation_at,              :timestamp, limit: 3,   null: true
+      t.column :close_in_min,                     :integer,               null: true
+      t.column :close_diff_in_min,                :integer,               null: true
+      t.column :update_escalation_at,             :timestamp, limit: 3,   null: true
+      t.column :update_in_min,                    :integer,               null: true
+      t.column :update_diff_in_min,               :integer,               null: true
+      t.column :last_contact_at,                  :timestamp, limit: 3,   null: true
+      t.column :last_contact_agent_at,            :timestamp, limit: 3,   null: true
+      t.column :last_contact_customer_at,         :timestamp, limit: 3,   null: true
       t.column :create_article_type_id,           :integer,               null: true
       t.column :create_article_sender_id,         :integer,               null: true
       t.column :article_count,                    :integer,               null: true
-      t.column :escalation_time,                  :timestamp, limit: 3,   null: true
+      t.column :escalation_at,                    :timestamp, limit: 3,   null: true
       t.column :pending_time,                     :timestamp, limit: 3,   null: true
       t.column :type,                             :string,    limit: 100, null: true
       t.column :preferences,                      :text,      limit: 500.kilobytes + 1, null: true
@@ -77,20 +74,20 @@ class CreateTicket < ActiveRecord::Migration
     add_index :tickets, [:number], unique: true
     add_index :tickets, [:title]
     add_index :tickets, [:created_at]
-    add_index :tickets, [:first_response]
-    add_index :tickets, [:first_response_escal_date]
+    add_index :tickets, [:first_response_at]
+    add_index :tickets, [:first_response_escalation_at]
     add_index :tickets, [:first_response_in_min]
     add_index :tickets, [:first_response_diff_in_min]
-    add_index :tickets, [:close_time]
-    add_index :tickets, [:close_time_escal_date]
-    add_index :tickets, [:close_time_in_min]
-    add_index :tickets, [:close_time_diff_in_min]
-    add_index :tickets, [:escalation_time]
-    add_index :tickets, [:update_time_in_min]
-    add_index :tickets, [:update_time_diff_in_min]
-    add_index :tickets, [:last_contact]
-    add_index :tickets, [:last_contact_agent]
-    add_index :tickets, [:last_contact_customer]
+    add_index :tickets, [:close_at]
+    add_index :tickets, [:close_escalation_at]
+    add_index :tickets, [:close_in_min]
+    add_index :tickets, [:close_diff_in_min]
+    add_index :tickets, [:escalation_at]
+    add_index :tickets, [:update_in_min]
+    add_index :tickets, [:update_diff_in_min]
+    add_index :tickets, [:last_contact_at]
+    add_index :tickets, [:last_contact_agent_at]
+    add_index :tickets, [:last_contact_customer_at]
     add_index :tickets, [:create_article_type_id]
     add_index :tickets, [:create_article_sender_id]
     add_index :tickets, [:created_by_id]
diff --git a/db/migrate/20160913000002_ticket_rename.rb b/db/migrate/20160913000002_ticket_rename.rb
new file mode 100644
index 000000000..836d7f3eb
--- /dev/null
+++ b/db/migrate/20160913000002_ticket_rename.rb
@@ -0,0 +1,54 @@
+class TicketRename < ActiveRecord::Migration
+  def up
+    # return if it's a new setup
+    return if !Setting.find_by(name: 'system_init_done')
+
+    rename_column :tickets, :first_response, :first_response_at
+    rename_column :tickets, :first_response_escal_date, :first_response_escalation_at
+
+    rename_column :tickets, :close_time, :close_at
+    rename_column :tickets, :close_time_escal_date, :close_escalation_at
+    rename_column :tickets, :close_time_in_min, :close_in_min
+    rename_column :tickets, :close_time_diff_in_min, :close_diff_in_min
+
+    rename_column :tickets, :update_time_escal_date, :update_escalation_at
+    rename_column :tickets, :update_time_in_min, :update_in_min
+    rename_column :tickets, :update_time_diff_in_min, :update_diff_in_min
+
+    rename_column :tickets, :escalation_time, :escalation_at
+
+    rename_column :tickets, :last_contact, :last_contact_at
+    rename_column :tickets, :last_contact_agent, :last_contact_agent_at
+    rename_column :tickets, :last_contact_customer, :last_contact_customer_at
+
+    remove_column :tickets, :first_response_sla_time
+    remove_column :tickets, :close_time_sla_time
+    remove_column :tickets, :update_time_sla_time
+
+    overview_role = Role.find_by(name: 'Agent')
+    Overview.create_or_update(
+      name: 'Escalated',
+      link: 'all_escalated',
+      prio: 1050,
+      role_id: overview_role.id,
+      condition: {
+        'ticket.escalation_at' => {
+          operator: 'within next (relative)',
+          value: '10',
+          range: 'minute',
+        },
+      },
+      order: {
+        by: 'escalation_at',
+        direction: 'ASC',
+      },
+      view: {
+        d: %w(title customer group owner escalation_at),
+        s: %w(title customer group owner escalation_at),
+        m: %w(number title customer group owner escalation_at),
+        view_mode_default: 's',
+      },
+    )
+
+  end
+end
diff --git a/db/seeds.rb b/db/seeds.rb
index 8f9fb8e95..0e6521110 100644
--- a/db/seeds.rb
+++ b/db/seeds.rb
@@ -3219,20 +3219,20 @@ Overview.create_if_not_exists(
   prio: 1050,
   role_id: overview_role.id,
   condition: {
-    'ticket.escalation_time' => {
+    'ticket.escalation_at' => {
       operator: 'within next (relative)',
       value: '10',
       range: 'minute',
     },
   },
   order: {
-    by: 'escalation_time',
+    by: 'escalation_at',
     direction: 'ASC',
   },
   view: {
-    d: %w(title customer group owner escalation_time),
-    s: %w(title customer group owner escalation_time),
-    m: %w(number title customer group owner escalation_time),
+    d: %w(title customer group owner escalation_at),
+    s: %w(title customer group owner escalation_at),
+    m: %w(number title customer group owner escalation_at),
     view_mode_default: 's',
   },
 )
diff --git a/lib/calendar_subscriptions/tickets.rb b/lib/calendar_subscriptions/tickets.rb
index c300f7b2d..2a5151c8e 100644
--- a/lib/calendar_subscriptions/tickets.rb
+++ b/lib/calendar_subscriptions/tickets.rb
@@ -172,7 +172,7 @@ class CalendarSubscriptions::Tickets
         operator: 'is',
         value: owner_ids,
       },
-      'ticket.escalation_time' => {
+      'ticket.escalation_at' => {
         operator: 'is not',
         value: nil,
       }
@@ -189,17 +189,17 @@ class CalendarSubscriptions::Tickets
 
     tickets.each do |ticket|
 
-      next if !ticket.escalation_time
+      next if !ticket.escalation_at
 
       event_data = {}
 
-      escalation_time = ticket.escalation_time
-      if escalation_time < Time.zone.today
-        escalation_time = Time.zone.today
+      escalation_at = ticket.escalation_at
+      if escalation_at < Time.zone.today
+        escalation_at = Time.zone.today
       end
 
-      event_data[:dtstart]     = Icalendar::Values::DateTime.new(escalation_time, 'tzid' => @tzid)
-      event_data[:dtend]       = Icalendar::Values::DateTime.new(escalation_time, 'tzid' => @tzid)
+      event_data[:dtstart]     = Icalendar::Values::DateTime.new(escalation_at, 'tzid' => @tzid)
+      event_data[:dtend]       = Icalendar::Values::DateTime.new(escalation_at, 'tzid' => @tzid)
       event_data[:summary]     = "#{translated_ticket_escalation}: '#{ticket.title}' #{customer}: #{ticket.customer.longname}"
       event_data[:description] = "T##{ticket.number}"
       if alarm?
diff --git a/lib/import/otrs.rb b/lib/import/otrs.rb
index eaf1e7eb9..49ad0d0f5 100644
--- a/lib/import/otrs.rb
+++ b/lib/import/otrs.rb
@@ -561,14 +561,14 @@ module Import::OTRS
         CustomerUserID: :customer,
         Title: :title,
         TicketID: :id,
-        FirstResponse: :first_response,
-        #FirstResponseTimeDestinationDate: :first_response_escal_date,
+        FirstResponse: :first_response_at,
+        #FirstResponseTimeDestinationDate: :first_response_escalation_at,
         #FirstResponseInMin: :first_response_in_min,
         #FirstResponseDiffInMin: :first_response_diff_in_min,
-        Closed: :close_time,
-        #SoltutionTimeDestinationDate: :close_time_escal_date,
-        #CloseTimeInMin: :close_time_in_min,
-        #CloseTimeDiffInMin: :close_time_diff_in_min,
+        Closed: :close_at,
+        #SoltutionTimeDestinationDate: :close_escalation_at,
+        #CloseTimeInMin: :close_in_min,
+        #CloseTimeDiffInMin: :close_diff_in_min,
       },
       Article: {
         SenderType: :sender,
diff --git a/lib/report/ticket_backlog.rb b/lib/report/ticket_backlog.rb
index 345119364..5948ae0a3 100644
--- a/lib/report/ticket_backlog.rb
+++ b/lib/report/ticket_backlog.rb
@@ -23,7 +23,7 @@ returns
     local_params[:params][:field] = 'created_at'
     created = Report::TicketGenericTime.aggs(local_params)
 
-    local_params[:params][:field] = 'close_time'
+    local_params[:params][:field] = 'close_at'
     closed = Report::TicketGenericTime.aggs(local_params)
 
     result = []
diff --git a/lib/report/ticket_first_solution.rb b/lib/report/ticket_first_solution.rb
index ee8b1924a..f54f41125 100644
--- a/lib/report/ticket_first_solution.rb
+++ b/lib/report/ticket_first_solution.rb
@@ -51,14 +51,14 @@ returns
         stop = start + 1.minute
       end
       query, bind_params, tables = Ticket.selector2sql(params[:selector])
-      ticket_list = Ticket.select('tickets.id, tickets.close_time, tickets.created_at').where(
-        'tickets.close_time IS NOT NULL AND tickets.close_time >= ? AND tickets.close_time < ?',
+      ticket_list = Ticket.select('tickets.id, tickets.close_at, tickets.created_at').where(
+        'tickets.close_at IS NOT NULL AND tickets.close_at >= ? AND tickets.close_at < ?',
         start,
         stop,
       ).where(query, *bind_params).joins(tables)
       count = 0
       ticket_list.each { |ticket|
-        closed_at  = ticket.close_time
+        closed_at  = ticket.close_at
         created_at = ticket.created_at
         if (closed_at - (60 * 15) ) < created_at
           count += 1
@@ -90,8 +90,8 @@ returns
 
   def self.items(params)
     query, bind_params, tables = Ticket.selector2sql(params[:selector])
-    ticket_list = Ticket.select('tickets.id, tickets.close_time, tickets.created_at').where(
-      'tickets.close_time IS NOT NULL AND tickets.close_time >= ? AND tickets.close_time < ?',
+    ticket_list = Ticket.select('tickets.id, tickets.close_at, tickets.created_at').where(
+      'tickets.close_at IS NOT NULL AND tickets.close_at >= ? AND tickets.close_at < ?',
       params[:range_start],
       params[:range_end],
     ).where(query, *bind_params).joins(tables)
@@ -99,7 +99,7 @@ returns
     assets = {}
     ticket_ids = []
     ticket_list.each { |ticket|
-      closed_at  = ticket.close_time
+      closed_at  = ticket.close_at
       created_at = ticket.created_at
       if (closed_at - (60 * 15) ) < created_at
         count += 1
diff --git a/lib/stats/ticket_escalation.rb b/lib/stats/ticket_escalation.rb
index 1cc2a25b5..0562eedc6 100644
--- a/lib/stats/ticket_escalation.rb
+++ b/lib/stats/ticket_escalation.rb
@@ -11,12 +11,12 @@ class Stats::TicketEscalation
 
     # owned tickets
     own_escalated = Ticket.where(
-      'owner_id = ? AND group_id IN (?) AND state_id IN (?) AND escalation_time < ?', user.id, group_ids, open_state_ids, Time.zone.now
+      'owner_id = ? AND group_id IN (?) AND state_id IN (?) AND escalation_at < ?', user.id, group_ids, open_state_ids, Time.zone.now
     ).count
 
     # all tickets
     all_escalated = Ticket.where(
-      'group_id IN (?) AND state_id IN (?) AND escalation_time < ?', group_ids, open_state_ids, Time.zone.now
+      'group_id IN (?) AND state_id IN (?) AND escalation_at < ?', group_ids, open_state_ids, Time.zone.now
     ).count
 
     average = '-'
diff --git a/lib/stats/ticket_in_process.rb b/lib/stats/ticket_in_process.rb
index c76678d19..97ef92788 100644
--- a/lib/stats/ticket_in_process.rb
+++ b/lib/stats/ticket_in_process.rb
@@ -15,7 +15,7 @@ class Stats::TicketInProcess
     # get all tickets where I worked on today (owner & closed today)
     closed_state_ids = Ticket::State.by_category('closed').map(&:id)
     closed_ticket_ids = Ticket.select('id').where(
-      'owner_id = ? AND state_id IN (?) AND close_time > ?',
+      'owner_id = ? AND state_id IN (?) AND close_at > ?',
       user.id, closed_state_ids, Time.zone.now - 1.day
     ).limit(100).map(&:id)
 
diff --git a/lib/stats/ticket_reopen.rb b/lib/stats/ticket_reopen.rb
index 4107cd770..b73dab3db 100644
--- a/lib/stats/ticket_reopen.rb
+++ b/lib/stats/ticket_reopen.rb
@@ -6,7 +6,7 @@ class Stats::TicketReopen
 
     # get my closed tickets
     total = Ticket.select('id').where(
-      'owner_id = ? AND close_time > ?',
+      'owner_id = ? AND close_at > ?',
       user.id, Time.zone.now - 7.days
     ).count
 
@@ -67,8 +67,8 @@ class Stats::TicketReopen
     return if object != 'Ticket'
     ticket = Ticket.lookup(id: o_id)
 
-    # check if close_time is already set / if not, ticket is not reopend
-    return if !ticket.close_time
+    # check if close_at is already set / if not, ticket is not reopend
+    return if !ticket.close_at
 
     # only if state id has changed
     return if !changes['state_id']
diff --git a/lib/stats/ticket_response_time.rb b/lib/stats/ticket_response_time.rb
index a896b0269..bf458cf93 100644
--- a/lib/stats/ticket_response_time.rb
+++ b/lib/stats/ticket_response_time.rb
@@ -13,10 +13,10 @@ class Stats::TicketResponseTime
     return if ticket.owner_id != 1 && ticket.owner_id != article_created_by_id
 
     # return if customer send at least
-    return if ticket.last_contact_customer > ticket.last_contact_agent
+    return if ticket.last_contact_customer_at > ticket.last_contact_agent_at
 
     # TODO: only business hours
-    response_time_taken = ticket.last_contact_agent - ticket.last_contact_customer
+    response_time_taken = ticket.last_contact_agent_at - ticket.last_contact_customer_at
 
     (response_time_taken / 60).round
   end
diff --git a/test/integration/otrs_import_test.rb b/test/integration/otrs_import_test.rb
index da1fa9ba5..194e402f1 100644
--- a/test/integration/otrs_import_test.rb
+++ b/test/integration/otrs_import_test.rb
@@ -185,7 +185,7 @@ class OtrsImportTest < ActiveSupport::TestCase
     assert_equal( 'partner', ticket.customer.login )
     assert_equal( 'Partner der betreut', ticket.organization.name )
     assert_equal( Time.zone.parse('2014-11-20 22:33:41 +0000').gmtime.to_s, ticket.created_at.to_s )
-    assert_equal( nil, ticket.close_time )
+    assert_equal( nil, ticket.close_at )
 
     # check history
     #  - create entry
@@ -200,7 +200,7 @@ class OtrsImportTest < ActiveSupport::TestCase
     assert_equal( 'jn2', ticket.customer.login )
     assert_equal( 'Znuny GmbH', ticket.organization.name )
     assert_equal( Time.zone.parse('2014-11-20 23:24:20 +0000').gmtime.to_s, ticket.created_at.to_s )
-    assert_equal( Time.zone.parse('2014-11-20 23:24:20 +0000').gmtime.to_s, ticket.close_time.to_s )
+    assert_equal( Time.zone.parse('2014-11-20 23:24:20 +0000').gmtime.to_s, ticket.close_at.to_s )
 
     # check history
     #  - create entry
@@ -215,7 +215,7 @@ class OtrsImportTest < ActiveSupport::TestCase
     assert_equal( 'betreuterkunde2', ticket.customer.login )
     assert_equal( 'Noch ein betreuter Kunde', ticket.organization.name )
     assert_equal( Time.zone.parse('2014-11-21 00:17:40 +0000').gmtime.to_s, ticket.created_at.to_s )
-    assert_equal( Time.zone.parse('2014-11-21 00:21:08 +0000').gmtime.to_s, ticket.close_time.to_s )
+    assert_equal( Time.zone.parse('2014-11-21 00:21:08 +0000').gmtime.to_s, ticket.close_at.to_s )
 
     # ticket dynamic fields
     ticket = Ticket.find(591)
diff --git a/test/integration/report_test.rb b/test/integration/report_test.rb
index 9709ab6fe..344150b10 100644
--- a/test/integration/report_test.rb
+++ b/test/integration/report_test.rb
@@ -139,7 +139,7 @@ class ReportTest < ActiveSupport::TestCase
     customer_id: 2,
     state: Ticket::State.lookup(name: 'closed'),
     priority: Ticket::Priority.lookup(name: '2 normal'),
-    close_time: '2015-10-28 11:30:00 UTC',
+    close_at: '2015-10-28 11:30:00 UTC',
     created_at: '2015-10-28 10:30:00 UTC',
     updated_at: '2015-10-28 10:30:00 UTC',
     updated_by_id: 1,
@@ -167,7 +167,7 @@ class ReportTest < ActiveSupport::TestCase
     customer_id: 2,
     state: Ticket::State.lookup(name: 'closed'),
     priority: Ticket::Priority.lookup(name: '3 high'),
-    close_time: '2015-10-28 11:40:00 UTC',
+    close_at: '2015-10-28 11:40:00 UTC',
     created_at: '2015-10-28 11:30:00 UTC',
     updated_at: '2015-10-28 11:30:00 UTC',
     updated_by_id: 1,
@@ -199,7 +199,7 @@ class ReportTest < ActiveSupport::TestCase
     customer_id: 2,
     state: Ticket::State.lookup(name: 'closed'),
     priority: Ticket::Priority.lookup(name: '2 normal'),
-    close_time: '2015-10-31 12:35:00 UTC',
+    close_at: '2015-10-31 12:35:00 UTC',
     created_at: '2015-10-31 12:30:00 UTC',
     updated_at: '2015-10-31 12:30:00 UTC',
     updated_by_id: 1,
@@ -227,7 +227,7 @@ class ReportTest < ActiveSupport::TestCase
     customer_id: 2,
     state: Ticket::State.lookup(name: 'closed'),
     priority: Ticket::Priority.lookup(name: '2 normal'),
-    close_time: '2015-11-01 12:30:00 UTC',
+    close_at: '2015-11-01 12:30:00 UTC',
     created_at: '2015-11-01 12:30:00 UTC',
     updated_at: '2015-11-01 12:30:00 UTC',
     updated_by_id: 1,
diff --git a/test/integration/zendesk_import_test.rb b/test/integration/zendesk_import_test.rb
index 1aafb5676..5b1c87082 100644
--- a/test/integration/zendesk_import_test.rb
+++ b/test/integration/zendesk_import_test.rb
@@ -437,27 +437,24 @@ If you\'re reading this message in your email, click the ticket number link that
       owner_id
       customer_id
       note
-      first_response
-      first_response_escal_date
-      first_response_sla_time
+      first_response_at
+      first_response_escalation_at
       first_response_in_min
       first_response_diff_in_min
-      close_time
-      close_time_escal_date
-      close_time_sla_time
-      close_time_in_min
-      close_time_diff_in_min
-      update_time_escal_date
-      update_time_sla_time
-      update_time_in_min
-      update_time_diff_in_min
-      last_contact
-      last_contact_agent
-      last_contact_customer
+      close_at
+      close_escalation_at
+      close_in_min
+      close_diff_in_min
+      update_escalation_at
+      update_in_min
+      update_diff_in_min
+      last_contact_at
+      last_contact_agent_at
+      last_contact_customer_at
       create_article_type_id
       create_article_sender_id
       article_count
-      escalation_time
+      escalation_at
       pending_time
       type
       preferences
diff --git a/test/unit/calendar_subscription_test.rb b/test/unit/calendar_subscription_test.rb
index 580dc6abf..3e31dbab1 100644
--- a/test/unit/calendar_subscription_test.rb
+++ b/test/unit/calendar_subscription_test.rb
@@ -134,7 +134,7 @@ class CalendarSubscriptionTest < ActiveSupport::TestCase
       updated_by_id: 1,
       created_by_id: 1,
     )
-    ticket5.update_columns(escalation_time: '2016-02-07 17:39:00')
+    ticket5.update_columns(escalation_at: '2016-02-07 17:39:00')
 
     ticket6 = Ticket.create!(
       title: 'some title1 - escalation - group_default',
@@ -147,7 +147,7 @@ class CalendarSubscriptionTest < ActiveSupport::TestCase
       updated_by_id: 1,
       created_by_id: 1,
     )
-    ticket6.update_columns(escalation_time: '2016-02-07 16:37:00')
+    ticket6.update_columns(escalation_at: '2016-02-07 16:37:00')
 
     ticket7 = Ticket.create!(
       title: 'some title2 - new - group_calendar',
@@ -206,7 +206,7 @@ class CalendarSubscriptionTest < ActiveSupport::TestCase
       updated_by_id: 1,
       created_by_id: 1,
     )
-    ticket11.update_columns(escalation_time: '2016-02-08 18:37:00')
+    ticket11.update_columns(escalation_at: '2016-02-08 18:37:00')
 
     ticket12 = Ticket.create!(
       title: 'some title2 - escalation - group_default',
@@ -219,8 +219,8 @@ class CalendarSubscriptionTest < ActiveSupport::TestCase
       updated_by_id: 1,
       created_by_id: 1,
     )
-    ticket12.update_columns(escalation_time: '2016-02-08 18:38:00')
-    Cache.clear # set escalation_time manually, to clear cache to have correct content later
+    ticket12.update_columns(escalation_at: '2016-02-08 18:38:00')
+    Cache.clear # set escalation_at manually, to clear cache to have correct content later
 
     # check agent 1
     calendar_subscriptions = CalendarSubscriptions.new(agent1)
diff --git a/test/unit/ticket_selector_test.rb b/test/unit/ticket_selector_test.rb
index 2d602b7f2..2d7039d12 100644
--- a/test/unit/ticket_selector_test.rb
+++ b/test/unit/ticket_selector_test.rb
@@ -129,7 +129,7 @@ class TicketSelectorTest < ActiveSupport::TestCase
       updated_by_id: 1,
       created_by_id: 1,
     )
-    ticket3.update_columns(escalation_time: '2015-02-06 10:00:00')
+    ticket3.update_columns(escalation_at: '2015-02-06 10:00:00')
     assert(ticket3, 'ticket created')
     assert_equal(ticket3.customer.id, customer2.id)
     assert_equal(ticket3.organization_id, nil)
@@ -287,7 +287,7 @@ class TicketSelectorTest < ActiveSupport::TestCase
     assert_equal(ticket_count, 1)
 
     condition = {
-      'ticket.escalation_time' => {
+      'ticket.escalation_at' => {
         operator: 'is not',
         value: nil,
       }
diff --git a/test/unit/ticket_sla_test.rb b/test/unit/ticket_sla_test.rb
index d81318700..5e6a27e3c 100644
--- a/test/unit/ticket_sla_test.rb
+++ b/test/unit/ticket_sla_test.rb
@@ -23,7 +23,7 @@ class TicketSlaTest < ActiveSupport::TestCase
       created_by_id: 1,
     )
     assert(ticket, 'ticket created')
-    assert_equal(ticket.escalation_time, nil, 'ticket.escalation_time verify')
+    assert_equal(ticket.escalation_at, nil, 'ticket.escalation_at verify')
 
     calendar1 = Calendar.create_or_update(
       name: 'EU 1',
@@ -76,10 +76,10 @@ class TicketSlaTest < ActiveSupport::TestCase
     )
     Scheduler.worker(true)
     ticket = Ticket.find(ticket.id)
-    assert_equal(ticket.escalation_time.gmtime.to_s, '2013-03-21 10:30:00 UTC', 'ticket.escalation_time verify 1')
-    assert_equal(ticket.first_response_escal_date.gmtime.to_s, '2013-03-21 10:30:00 UTC', 'ticket.first_response_escal_date verify 1')
-    assert_equal(ticket.update_time_escal_date.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.update_time_escal_date verify 1')
-    assert_equal(ticket.close_time_escal_date.gmtime.to_s, '2013-03-21 13:30:00 UTC', 'ticket.close_time_escal_date verify 1')
+    assert_equal(ticket.escalation_at.gmtime.to_s, '2013-03-21 10:30:00 UTC', 'ticket.escalation_at verify 1')
+    assert_equal(ticket.first_response_escalation_at.gmtime.to_s, '2013-03-21 10:30:00 UTC', 'ticket.first_response_escalation_at verify 1')
+    assert_equal(ticket.update_escalation_at.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.update_escalation_at verify 1')
+    assert_equal(ticket.close_escalation_at.gmtime.to_s, '2013-03-21 13:30:00 UTC', 'ticket.close_escalation_at verify 1')
 
     sla = Sla.create_or_update(
       name: 'test sla 1',
@@ -93,10 +93,10 @@ class TicketSlaTest < ActiveSupport::TestCase
     )
     Scheduler.worker(true)
     ticket = Ticket.find(ticket.id)
-    assert_equal(ticket.escalation_time.gmtime.to_s, '2013-03-21 11:30:00 UTC', 'ticket.escalation_time verify 1')
-    assert_equal(ticket.first_response_escal_date.gmtime.to_s, '2013-03-21 11:30:00 UTC', 'ticket.first_response_escal_date verify 1')
-    assert_equal(ticket.update_time_escal_date.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.update_time_escal_date verify 1')
-    assert_equal(ticket.close_time_escal_date.gmtime.to_s, '2013-03-21 13:30:00 UTC', 'ticket.close_time_escal_date verify 1')
+    assert_equal(ticket.escalation_at.gmtime.to_s, '2013-03-21 11:30:00 UTC', 'ticket.escalation_at verify 1')
+    assert_equal(ticket.first_response_escalation_at.gmtime.to_s, '2013-03-21 11:30:00 UTC', 'ticket.first_response_escalation_at verify 1')
+    assert_equal(ticket.update_escalation_at.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.update_escalation_at verify 1')
+    assert_equal(ticket.close_escalation_at.gmtime.to_s, '2013-03-21 13:30:00 UTC', 'ticket.close_escalation_at verify 1')
     delete = sla.destroy
     assert(delete, 'sla destroy 1')
 
@@ -155,190 +155,190 @@ class TicketSlaTest < ActiveSupport::TestCase
     )
     Scheduler.worker(true)
     ticket = Ticket.find(ticket.id)
-    assert_equal(ticket.escalation_time.gmtime.to_s, '2013-03-21 10:30:00 UTC', 'ticket.escalation_time verify 2')
-    assert_equal(ticket.first_response_escal_date.gmtime.to_s, '2013-03-21 10:30:00 UTC', 'ticket.first_response_escal_date verify 2')
-    assert_equal(ticket.first_response, nil, 'ticket.first_response verify 2')
+    assert_equal(ticket.escalation_at.gmtime.to_s, '2013-03-21 10:30:00 UTC', 'ticket.escalation_at verify 2')
+    assert_equal(ticket.first_response_escalation_at.gmtime.to_s, '2013-03-21 10:30:00 UTC', 'ticket.first_response_escalation_at verify 2')
+    assert_equal(ticket.first_response_at, nil, 'ticket.first_response_at verify 2')
     assert_equal(ticket.first_response_in_min, nil, 'ticket.first_response_in_min verify 2')
     assert_equal(ticket.first_response_diff_in_min, nil, 'ticket.first_response_diff_in_min verify 2')
 
-    assert_equal(ticket.update_time_escal_date.gmtime.to_s, '2013-03-21 11:30:00 UTC', 'ticket.update_time_escal_date verify 2')
-    assert_equal(ticket.update_time_in_min, nil, 'ticket.update_time_in_min verify 2')
-    assert_equal(ticket.update_time_diff_in_min, nil, 'ticket.update_time_diff_in_min verify 2')
+    assert_equal(ticket.update_escalation_at.gmtime.to_s, '2013-03-21 11:30:00 UTC', 'ticket.update_escalation_at verify 2')
+    assert_equal(ticket.update_in_min, nil, 'ticket.update_in_min verify 2')
+    assert_equal(ticket.update_diff_in_min, nil, 'ticket.update_diff_in_min verify 2')
 
-    assert_equal(ticket.close_time_escal_date.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.close_time_escal_date verify 2')
-    assert_equal(ticket.close_time_in_min, nil, 'ticket.close_time_in_min verify 2')
-    assert_equal(ticket.close_time_diff_in_min, nil, 'ticket.close_time_diff_in_min verify 2')
+    assert_equal(ticket.close_escalation_at.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.close_escalation_at verify 2')
+    assert_equal(ticket.close_in_min, nil, 'ticket.close_in_min verify 2')
+    assert_equal(ticket.close_diff_in_min, nil, 'ticket.close_diff_in_min verify 2')
 
     # set first response in time
     ticket.update_attributes(
-      first_response: '2013-03-21 10:00:00 UTC',
+      first_response_at: '2013-03-21 10:00:00 UTC',
     )
 
-    assert_equal(ticket.escalation_time.gmtime.to_s, '2013-03-21 11:30:00 UTC', 'ticket.escalation_time verify 3')
-    assert_equal(ticket.first_response_escal_date.gmtime.to_s, '2013-03-21 10:30:00 UTC', 'ticket.first_response_escal_date verify 3')
-    assert_equal(ticket.first_response.gmtime.to_s, '2013-03-21 10:00:00 UTC', 'ticket.first_response verify 3')
+    assert_equal(ticket.escalation_at.gmtime.to_s, '2013-03-21 11:30:00 UTC', 'ticket.escalation_at verify 3')
+    assert_equal(ticket.first_response_escalation_at.gmtime.to_s, '2013-03-21 10:30:00 UTC', 'ticket.first_response_escalation_at verify 3')
+    assert_equal(ticket.first_response_at.gmtime.to_s, '2013-03-21 10:00:00 UTC', 'ticket.first_response_at verify 3')
     assert_equal(ticket.first_response_in_min, 30, 'ticket.first_response_in_min verify 3')
     assert_equal(ticket.first_response_diff_in_min, 30, 'ticket.first_response_diff_in_min verify 3')
 
-    assert_equal(ticket.update_time_escal_date.gmtime.to_s, '2013-03-21 11:30:00 UTC', 'ticket.update_time_escal_date verify 3')
-    assert_equal(ticket.update_time_in_min, nil, 'ticket.update_time_in_min verify 3')
-    assert_equal(ticket.update_time_diff_in_min, nil, 'ticket.update_time_diff_in_min verify 3')
+    assert_equal(ticket.update_escalation_at.gmtime.to_s, '2013-03-21 11:30:00 UTC', 'ticket.update_escalation_at verify 3')
+    assert_equal(ticket.update_in_min, nil, 'ticket.update_in_min verify 3')
+    assert_equal(ticket.update_diff_in_min, nil, 'ticket.update_diff_in_min verify 3')
 
-    assert_equal(ticket.close_time_escal_date.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.close_time_escal_date verify 3')
-    assert_equal(ticket.close_time_in_min, nil, 'ticket.close_time_in_min verify 3')
-    assert_equal(ticket.close_time_diff_in_min, nil, 'ticket.close_time_diff_in_min verify 3')
+    assert_equal(ticket.close_escalation_at.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.close_escalation_at verify 3')
+    assert_equal(ticket.close_in_min, nil, 'ticket.close_in_min verify 3')
+    assert_equal(ticket.close_diff_in_min, nil, 'ticket.close_diff_in_min verify 3')
 
     # set first reponse over time
     ticket.update_attributes(
-      first_response: '2013-03-21 14:00:00 UTC',
+      first_response_at: '2013-03-21 14:00:00 UTC',
     )
 
-    assert_equal(ticket.escalation_time.gmtime.to_s, '2013-03-21 11:30:00 UTC', 'ticket.escalation_time verify 4')
-    assert_equal(ticket.first_response_escal_date.gmtime.to_s, '2013-03-21 10:30:00 UTC', 'ticket.first_response_escal_date verify 4')
-    assert_equal(ticket.first_response.gmtime.to_s, '2013-03-21 14:00:00 UTC', 'ticket.first_response verify 4')
+    assert_equal(ticket.escalation_at.gmtime.to_s, '2013-03-21 11:30:00 UTC', 'ticket.escalation_at verify 4')
+    assert_equal(ticket.first_response_escalation_at.gmtime.to_s, '2013-03-21 10:30:00 UTC', 'ticket.first_response_escalation_at verify 4')
+    assert_equal(ticket.first_response_at.gmtime.to_s, '2013-03-21 14:00:00 UTC', 'ticket.first_response_at verify 4')
     assert_equal(ticket.first_response_in_min, 270, 'ticket.first_response_in_min verify 4')
     assert_equal(ticket.first_response_diff_in_min, -210, 'ticket.first_response_diff_in_min verify 4')
 
-    assert_equal(ticket.update_time_escal_date.gmtime.to_s, '2013-03-21 11:30:00 UTC', 'ticket.update_time_escal_date verify 4')
-    assert_equal(ticket.update_time_in_min, nil, 'ticket.update_time_in_min verify 4')
-    assert_equal(ticket.update_time_diff_in_min, nil, 'ticket.update_time_diff_in_min verify 4')
+    assert_equal(ticket.update_escalation_at.gmtime.to_s, '2013-03-21 11:30:00 UTC', 'ticket.update_escalation_at verify 4')
+    assert_equal(ticket.update_in_min, nil, 'ticket.update_in_min verify 4')
+    assert_equal(ticket.update_diff_in_min, nil, 'ticket.update_diff_in_min verify 4')
 
-    assert_equal(ticket.close_time_escal_date.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.close_time_escal_date verify 4')
-    assert_equal(ticket.close_time_in_min, nil, 'ticket.close_time_in_min verify 4')
-    assert_equal(ticket.close_time_diff_in_min, nil, 'ticket.close_time_diff_in_min verify 4')
+    assert_equal(ticket.close_escalation_at.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.close_escalation_at verify 4')
+    assert_equal(ticket.close_in_min, nil, 'ticket.close_in_min verify 4')
+    assert_equal(ticket.close_diff_in_min, nil, 'ticket.close_diff_in_min verify 4')
 
     # set update time in time
     ticket.update_attributes(
-      last_contact_agent: '2013-03-21 11:00:00 UTC',
+      last_contact_agent_at: '2013-03-21 11:00:00 UTC',
     )
-    assert_equal(ticket.escalation_time.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.escalation_time verify 5')
+    assert_equal(ticket.escalation_at.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.escalation_at verify 5')
 
-    assert_equal(ticket.first_response_escal_date.gmtime.to_s, '2013-03-21 10:30:00 UTC', 'ticket.first_response_escal_date verify 5')
-    assert_equal(ticket.first_response.gmtime.to_s, '2013-03-21 14:00:00 UTC', 'ticket.first_response verify 5')
+    assert_equal(ticket.first_response_escalation_at.gmtime.to_s, '2013-03-21 10:30:00 UTC', 'ticket.first_response_escalation_at verify 5')
+    assert_equal(ticket.first_response_at.gmtime.to_s, '2013-03-21 14:00:00 UTC', 'ticket.first_response_at verify 5')
     assert_equal(ticket.first_response_in_min, 270, 'ticket.first_response_in_min verify 5')
     assert_equal(ticket.first_response_diff_in_min, -210, 'ticket.first_response_diff_in_min verify 5')
 
-    assert_equal(ticket.update_time_escal_date.gmtime.to_s, '2013-03-21 13:00:00 UTC', 'ticket.update_time_escal_date verify 5')
-    assert_equal(ticket.update_time_in_min, 90, 'ticket.update_time_in_min verify 5')
-    assert_equal(ticket.update_time_diff_in_min, 30, 'ticket.update_time_diff_in_min verify 5')
+    assert_equal(ticket.update_escalation_at.gmtime.to_s, '2013-03-21 13:00:00 UTC', 'ticket.update_escalation_at verify 5')
+    assert_equal(ticket.update_in_min, 90, 'ticket.update_in_min verify 5')
+    assert_equal(ticket.update_diff_in_min, 30, 'ticket.update_diff_in_min verify 5')
 
-    assert_equal(ticket.close_time_escal_date.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.close_time_escal_date verify 5')
-    assert_equal(ticket.close_time_in_min, nil, 'ticket.close_time_in_min verify 5')
-    assert_equal(ticket.close_time_diff_in_min, nil, 'ticket.close_time_diff_in_min verify 5')
+    assert_equal(ticket.close_escalation_at.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.close_escalation_at verify 5')
+    assert_equal(ticket.close_in_min, nil, 'ticket.close_in_min verify 5')
+    assert_equal(ticket.close_diff_in_min, nil, 'ticket.close_diff_in_min verify 5')
 
     # set update time over time
     ticket.update_attributes(
-      last_contact_agent: '2013-03-21 12:00:00 UTC',
+      last_contact_agent_at: '2013-03-21 12:00:00 UTC',
     )
-    assert_equal(ticket.escalation_time.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.escalation_time verify 6')
+    assert_equal(ticket.escalation_at.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.escalation_at verify 6')
 
-    assert_equal(ticket.first_response_escal_date.gmtime.to_s, '2013-03-21 10:30:00 UTC', 'ticket.first_response_escal_date verify 6')
-    assert_equal(ticket.first_response.gmtime.to_s, '2013-03-21 14:00:00 UTC', 'ticket.first_response verify 6')
+    assert_equal(ticket.first_response_escalation_at.gmtime.to_s, '2013-03-21 10:30:00 UTC', 'ticket.first_response_escalation_at verify 6')
+    assert_equal(ticket.first_response_at.gmtime.to_s, '2013-03-21 14:00:00 UTC', 'ticket.first_response_at verify 6')
     assert_equal(ticket.first_response_in_min, 270, 'ticket.first_response_in_min verify 6')
     assert_equal(ticket.first_response_diff_in_min, -210, 'ticket.first_response_diff_in_min verify 6')
 
-    assert_equal(ticket.update_time_escal_date.gmtime.to_s, '2013-03-21 14:00:00 UTC', 'ticket.update_time_escal_date verify 6')
-    assert_equal(ticket.update_time_in_min, 150, 'ticket.update_time_in_min verify 6')
-    assert_equal(ticket.update_time_diff_in_min, -30, 'ticket.update_time_diff_in_min verify 6')
+    assert_equal(ticket.update_escalation_at.gmtime.to_s, '2013-03-21 14:00:00 UTC', 'ticket.update_escalation_at verify 6')
+    assert_equal(ticket.update_in_min, 150, 'ticket.update_in_min verify 6')
+    assert_equal(ticket.update_diff_in_min, -30, 'ticket.update_diff_in_min verify 6')
 
-    assert_equal(ticket.close_time_escal_date.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.close_time_escal_date verify 6')
-    assert_equal(ticket.close_time_in_min, nil, 'ticket.close_time_in_min verify 6')
-    assert_equal(ticket.close_time_diff_in_min, nil, 'ticket.close_time_diff_in_min verify 6')
+    assert_equal(ticket.close_escalation_at.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.close_escalation_at verify 6')
+    assert_equal(ticket.close_in_min, nil, 'ticket.close_in_min verify 6')
+    assert_equal(ticket.close_diff_in_min, nil, 'ticket.close_diff_in_min verify 6')
 
     # set update time over time
     ticket.update_attributes(
-      last_contact_customer: '2013-03-21 12:05:00 UTC',
+      last_contact_customer_at: '2013-03-21 12:05:00 UTC',
     )
-    assert_equal(ticket.escalation_time.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.escalation_time verify 6')
+    assert_equal(ticket.escalation_at.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.escalation_at verify 6')
 
-    assert_equal(ticket.first_response_escal_date.gmtime.to_s, '2013-03-21 10:30:00 UTC', 'ticket.first_response_escal_date verify 6')
-    assert_equal(ticket.first_response.gmtime.to_s, '2013-03-21 14:00:00 UTC', 'ticket.first_response verify 6')
+    assert_equal(ticket.first_response_escalation_at.gmtime.to_s, '2013-03-21 10:30:00 UTC', 'ticket.first_response_escalation_at verify 6')
+    assert_equal(ticket.first_response_at.gmtime.to_s, '2013-03-21 14:00:00 UTC', 'ticket.first_response_at verify 6')
     assert_equal(ticket.first_response_in_min, 270, 'ticket.first_response_in_min verify 6')
     assert_equal(ticket.first_response_diff_in_min, -210, 'ticket.first_response_diff_in_min verify 6')
 
-    assert_equal(ticket.update_time_escal_date.gmtime.to_s, '2013-03-21 14:05:00 UTC', 'ticket.update_time_escal_date verify 6')
-    assert_equal(ticket.update_time_in_min, 155, 'ticket.update_time_in_min verify 6')
-    assert_equal(ticket.update_time_diff_in_min, -35, 'ticket.update_time_diff_in_min verify 6')
+    assert_equal(ticket.update_escalation_at.gmtime.to_s, '2013-03-21 14:05:00 UTC', 'ticket.update_escalation_at verify 6')
+    assert_equal(ticket.update_in_min, 155, 'ticket.update_in_min verify 6')
+    assert_equal(ticket.update_diff_in_min, -35, 'ticket.update_diff_in_min verify 6')
 
-    assert_equal(ticket.close_time_escal_date.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.close_time_escal_date verify 6')
-    assert_equal(ticket.close_time_in_min, nil, 'ticket.close_time_in_min verify 6')
-    assert_equal(ticket.close_time_diff_in_min, nil, 'ticket.close_time_diff_in_min verify 6')
+    assert_equal(ticket.close_escalation_at.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.close_escalation_at verify 6')
+    assert_equal(ticket.close_in_min, nil, 'ticket.close_in_min verify 6')
+    assert_equal(ticket.close_diff_in_min, nil, 'ticket.close_diff_in_min verify 6')
 
     # set update time over time
     ticket.update_attributes(
-      last_contact_agent: '2013-03-21 12:10:00 UTC',
+      last_contact_agent_at: '2013-03-21 12:10:00 UTC',
     )
-    assert_equal(ticket.escalation_time.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.escalation_time verify 6')
+    assert_equal(ticket.escalation_at.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.escalation_at verify 6')
 
-    assert_equal(ticket.first_response_escal_date.gmtime.to_s, '2013-03-21 10:30:00 UTC', 'ticket.first_response_escal_date verify 6')
-    assert_equal(ticket.first_response.gmtime.to_s, '2013-03-21 14:00:00 UTC', 'ticket.first_response verify 6')
+    assert_equal(ticket.first_response_escalation_at.gmtime.to_s, '2013-03-21 10:30:00 UTC', 'ticket.first_response_escalation_at verify 6')
+    assert_equal(ticket.first_response_at.gmtime.to_s, '2013-03-21 14:00:00 UTC', 'ticket.first_response_at verify 6')
     assert_equal(ticket.first_response_in_min, 270, 'ticket.first_response_in_min verify 6')
     assert_equal(ticket.first_response_diff_in_min, -210, 'ticket.first_response_diff_in_min verify 6')
 
-    assert_equal(ticket.update_time_escal_date.gmtime.to_s, '2013-03-21 14:10:00 UTC', 'ticket.update_time_escal_date verify 6')
-    assert_equal(ticket.update_time_in_min, 160, 'ticket.update_time_in_min verify 6')
-    assert_equal(ticket.update_time_diff_in_min, -40, 'ticket.update_time_diff_in_min verify 6')
+    assert_equal(ticket.update_escalation_at.gmtime.to_s, '2013-03-21 14:10:00 UTC', 'ticket.update_escalation_at verify 6')
+    assert_equal(ticket.update_in_min, 160, 'ticket.update_in_min verify 6')
+    assert_equal(ticket.update_diff_in_min, -40, 'ticket.update_diff_in_min verify 6')
 
-    assert_equal(ticket.close_time_escal_date.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.close_time_escal_date verify 6')
-    assert_equal(ticket.close_time_in_min, nil, 'ticket.close_time_in_min verify 6')
-    assert_equal(ticket.close_time_diff_in_min, nil, 'ticket.close_time_diff_in_min verify 6')
+    assert_equal(ticket.close_escalation_at.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.close_escalation_at verify 6')
+    assert_equal(ticket.close_in_min, nil, 'ticket.close_in_min verify 6')
+    assert_equal(ticket.close_diff_in_min, nil, 'ticket.close_diff_in_min verify 6')
 
     # set close time in time
     ticket.update_attributes(
-      close_time: '2013-03-21 11:30:00 UTC',
+      close_at: '2013-03-21 11:30:00 UTC',
     )
-    assert_equal(ticket.escalation_time.gmtime.to_s, '2013-03-21 14:10:00 UTC', 'ticket.escalation_time verify 7')
+    assert_equal(ticket.escalation_at.gmtime.to_s, '2013-03-21 14:10:00 UTC', 'ticket.escalation_at verify 7')
 
-    assert_equal(ticket.first_response_escal_date.gmtime.to_s, '2013-03-21 10:30:00 UTC', 'ticket.first_response_escal_date verify 7')
-    assert_equal(ticket.first_response.gmtime.to_s, '2013-03-21 14:00:00 UTC', 'ticket.first_response verify 7')
+    assert_equal(ticket.first_response_escalation_at.gmtime.to_s, '2013-03-21 10:30:00 UTC', 'ticket.first_response_escalation_at verify 7')
+    assert_equal(ticket.first_response_at.gmtime.to_s, '2013-03-21 14:00:00 UTC', 'ticket.first_response_at verify 7')
     assert_equal(ticket.first_response_in_min, 270, 'ticket.first_response_in_min verify 7')
     assert_equal(ticket.first_response_diff_in_min, -210, 'ticket.first_response_diff_in_min verify 7')
 
-    assert_equal(ticket.update_time_escal_date.gmtime.to_s, '2013-03-21 14:10:00 UTC', 'ticket.update_time_escal_date verify 7')
-    assert_equal(ticket.update_time_in_min, 160, 'ticket.update_time_in_min verify 7')
-    assert_equal(ticket.update_time_diff_in_min, -40, 'ticket.update_time_diff_in_min verify 7')
+    assert_equal(ticket.update_escalation_at.gmtime.to_s, '2013-03-21 14:10:00 UTC', 'ticket.update_escalation_at verify 7')
+    assert_equal(ticket.update_in_min, 160, 'ticket.update_in_min verify 7')
+    assert_equal(ticket.update_diff_in_min, -40, 'ticket.update_diff_in_min verify 7')
 
-    assert_equal(ticket.close_time_escal_date.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.close_time_escal_date verify 7')
-    assert_equal(ticket.close_time_in_min, 120, 'ticket.close_time_in_min verify 7')
-    assert_equal(ticket.close_time_diff_in_min, 60, 'ticket.close_time_diff_in_min verify 7')
+    assert_equal(ticket.close_escalation_at.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.close_escalation_at verify 7')
+    assert_equal(ticket.close_in_min, 120, 'ticket.close_in_min verify 7')
+    assert_equal(ticket.close_diff_in_min, 60, 'ticket.close_diff_in_min verify 7')
 
     # set close time over time
     ticket.update_attributes(
-      close_time: '2013-03-21 13:00:00 UTC',
+      close_at: '2013-03-21 13:00:00 UTC',
     )
-    assert_equal(ticket.escalation_time.gmtime.to_s, '2013-03-21 14:10:00 UTC', 'ticket.escalation_time verify 8')
+    assert_equal(ticket.escalation_at.gmtime.to_s, '2013-03-21 14:10:00 UTC', 'ticket.escalation_at verify 8')
 
-    assert_equal(ticket.first_response_escal_date.gmtime.to_s, '2013-03-21 10:30:00 UTC', 'ticket.first_response_escal_date verify 8')
-    assert_equal(ticket.first_response.gmtime.to_s, '2013-03-21 14:00:00 UTC', 'ticket.first_response verify 8')
+    assert_equal(ticket.first_response_escalation_at.gmtime.to_s, '2013-03-21 10:30:00 UTC', 'ticket.first_response_escalation_at verify 8')
+    assert_equal(ticket.first_response_at.gmtime.to_s, '2013-03-21 14:00:00 UTC', 'ticket.first_response_at verify 8')
     assert_equal(ticket.first_response_in_min, 270, 'ticket.first_response_in_min verify 8')
     assert_equal(ticket.first_response_diff_in_min, -210, 'ticket.first_response_diff_in_min verify 8')
 
-    assert_equal(ticket.update_time_escal_date.gmtime.to_s, '2013-03-21 14:10:00 UTC', 'ticket.update_time_escal_date verify 8')
-    assert_equal(ticket.update_time_in_min, 160, 'ticket.update_time_in_min verify 8')
-    assert_equal(ticket.update_time_diff_in_min, -40, 'ticket.update_time_diff_in_min verify 8')
+    assert_equal(ticket.update_escalation_at.gmtime.to_s, '2013-03-21 14:10:00 UTC', 'ticket.update_escalation_at verify 8')
+    assert_equal(ticket.update_in_min, 160, 'ticket.update_in_min verify 8')
+    assert_equal(ticket.update_diff_in_min, -40, 'ticket.update_diff_in_min verify 8')
 
-    assert_equal(ticket.close_time_escal_date.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.close_time_escal_date verify 8')
-    assert_equal(ticket.close_time_in_min, 210, 'ticket.close_time_in_min verify 8')
-    assert_equal(ticket.close_time_diff_in_min, -30, 'ticket.close_time_diff_in_min verify 8')
+    assert_equal(ticket.close_escalation_at.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.close_escalation_at verify 8')
+    assert_equal(ticket.close_in_min, 210, 'ticket.close_in_min verify 8')
+    assert_equal(ticket.close_diff_in_min, -30, 'ticket.close_diff_in_min verify 8')
 
     # set close time over time
     ticket.update_attributes(
       state: Ticket::State.lookup(name: 'closed')
     )
-    assert_equal(ticket.escalation_time, nil, 'ticket.escalation_time verify 9')
+    assert_equal(ticket.escalation_at, nil, 'ticket.escalation_at verify 9')
 
-    assert_equal(ticket.first_response_escal_date.gmtime.to_s, '2013-03-21 10:30:00 UTC', 'ticket.first_response_escal_date verify 9')
-    assert_equal(ticket.first_response.gmtime.to_s, '2013-03-21 14:00:00 UTC', 'ticket.first_response verify 9')
+    assert_equal(ticket.first_response_escalation_at.gmtime.to_s, '2013-03-21 10:30:00 UTC', 'ticket.first_response_escalation_at verify 9')
+    assert_equal(ticket.first_response_at.gmtime.to_s, '2013-03-21 14:00:00 UTC', 'ticket.first_response_at verify 9')
     assert_equal(ticket.first_response_in_min, 270, 'ticket.first_response_in_min verify 9')
     assert_equal(ticket.first_response_diff_in_min, -210, 'ticket.first_response_diff_in_min verify 9')
 
-    assert_equal(ticket.update_time_escal_date.gmtime.to_s, '2013-03-21 14:10:00 UTC', 'ticket.update_time_escal_date verify 9')
-    assert_equal(ticket.update_time_in_min, 160, 'ticket.update_time_in_min verify 9')
-    assert_equal(ticket.update_time_diff_in_min, -40, 'ticket.update_time_diff_in_min verify 9')
+    assert_equal(ticket.update_escalation_at.gmtime.to_s, '2013-03-21 14:10:00 UTC', 'ticket.update_escalation_at verify 9')
+    assert_equal(ticket.update_in_min, 160, 'ticket.update_in_min verify 9')
+    assert_equal(ticket.update_diff_in_min, -40, 'ticket.update_diff_in_min verify 9')
 
-    assert_equal(ticket.close_time_escal_date.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.close_time_escal_date verify 9')
-    assert_equal(ticket.close_time_in_min, 210, 'ticket.close_time_in_min verify 9')
-    assert_equal(ticket.close_time_diff_in_min, -30, 'ticket.close_time_diff_in_min verify 9')
+    assert_equal(ticket.close_escalation_at.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.close_escalation_at verify 9')
+    assert_equal(ticket.close_in_min, 210, 'ticket.close_in_min verify 9')
+    assert_equal(ticket.close_diff_in_min, -30, 'ticket.close_diff_in_min verify 9')
 
     delete = ticket.destroy
     assert(delete, 'ticket destroy')
@@ -378,11 +378,11 @@ class TicketSlaTest < ActiveSupport::TestCase
     )
     ticket = Ticket.find(ticket.id)
     assert_equal(ticket.article_count, 1, 'ticket.article_count verify - inbound')
-    assert_equal(ticket.last_contact.to_s, article_inbound.created_at.to_s, 'ticket.last_contact verify - inbound')
-    assert_equal(ticket.last_contact_customer.to_s, article_inbound.created_at.to_s, 'ticket.last_contact_customer verify - inbound')
-    assert_equal(ticket.last_contact_agent, nil, 'ticket.last_contact_agent verify - inbound')
-    assert_equal(ticket.first_response, nil, 'ticket.first_response verify - inbound')
-    assert_equal(ticket.close_time, nil, 'ticket.close_time verify - inbound')
+    assert_equal(ticket.last_contact_at.to_s, article_inbound.created_at.to_s, 'ticket.last_contact_at verify - inbound')
+    assert_equal(ticket.last_contact_customer_at.to_s, article_inbound.created_at.to_s, 'ticket.last_contact_customer_at verify - inbound')
+    assert_equal(ticket.last_contact_agent_at, nil, 'ticket.last_contact_agent_at verify - inbound')
+    assert_equal(ticket.first_response_at, nil, 'ticket.first_response_at verify - inbound')
+    assert_equal(ticket.close_at, nil, 'ticket.close_at verify - inbound')
 
     # create outbound article
     article_outbound = Ticket::Article.create!(
@@ -403,13 +403,13 @@ class TicketSlaTest < ActiveSupport::TestCase
 
     ticket = Ticket.find(ticket.id)
     assert_equal(ticket.article_count, 2, 'ticket.article_count verify - outbound')
-    assert_equal(ticket.last_contact.to_s, article_outbound.created_at.to_s, 'ticket.last_contact verify - outbound')
-    assert_equal(ticket.last_contact_customer.to_s, article_inbound.created_at.to_s, 'ticket.last_contact_customer verify - outbound')
-    assert_equal(ticket.last_contact_agent.to_s, article_outbound.created_at.to_s, 'ticket.last_contact_agent verify - outbound')
-    assert_equal(ticket.first_response.to_s, article_outbound.created_at.to_s, 'ticket.first_response verify - outbound')
+    assert_equal(ticket.last_contact_at.to_s, article_outbound.created_at.to_s, 'ticket.last_contact_at verify - outbound')
+    assert_equal(ticket.last_contact_customer_at.to_s, article_inbound.created_at.to_s, 'ticket.last_contact_customer_at verify - outbound')
+    assert_equal(ticket.last_contact_agent_at.to_s, article_outbound.created_at.to_s, 'ticket.last_contact_agent_at verify - outbound')
+    assert_equal(ticket.first_response_at.to_s, article_outbound.created_at.to_s, 'ticket.first_response_at verify - outbound')
     assert_equal(ticket.first_response_in_min, 0, 'ticket.first_response_in_min verify - outbound')
     assert_equal(ticket.first_response_diff_in_min, 60, 'ticket.first_response_diff_in_min verify - outbound')
-    assert_equal(ticket.close_time, nil, 'ticket.close_time verify - outbound')
+    assert_equal(ticket.close_at, nil, 'ticket.close_at verify - outbound')
 
     delete = ticket.destroy
     assert(delete, 'ticket destroy')
@@ -448,11 +448,11 @@ class TicketSlaTest < ActiveSupport::TestCase
     )
     ticket = Ticket.find(ticket.id)
     assert_equal(ticket.article_count, 1, 'ticket.article_count verify - inbound')
-    assert_equal(ticket.last_contact.to_s, article_inbound.created_at.to_s, 'ticket.last_contact verify - inbound')
-    assert_equal(ticket.last_contact_customer.to_s, article_inbound.created_at.to_s, 'ticket.last_contact_customer verify - inbound')
-    assert_equal(ticket.last_contact_agent, nil, 'ticket.last_contact_agent verify - inbound')
-    assert_equal(ticket.first_response, nil, 'ticket.first_response verify - inbound')
-    assert_equal(ticket.close_time, nil, 'ticket.close_time verify - inbound')
+    assert_equal(ticket.last_contact_at.to_s, article_inbound.created_at.to_s, 'ticket.last_contact_at verify - inbound')
+    assert_equal(ticket.last_contact_customer_at.to_s, article_inbound.created_at.to_s, 'ticket.last_contact_customer_at verify - inbound')
+    assert_equal(ticket.last_contact_agent_at, nil, 'ticket.last_contact_agent_at verify - inbound')
+    assert_equal(ticket.first_response_at, nil, 'ticket.first_response_at verify - inbound')
+    assert_equal(ticket.close_at, nil, 'ticket.close_at verify - inbound')
 
     # create note article
     article_note = Ticket::Article.create!(
@@ -471,11 +471,11 @@ class TicketSlaTest < ActiveSupport::TestCase
     )
     ticket = Ticket.find(ticket.id)
     assert_equal(ticket.article_count, 2, 'ticket.article_count verify - inbound')
-    assert_equal(ticket.last_contact.to_s, article_inbound.created_at.to_s, 'ticket.last_contact verify - inbound')
-    assert_equal(ticket.last_contact_customer.to_s, article_inbound.created_at.to_s, 'ticket.last_contact_customer verify - inbound')
-    assert_equal(ticket.last_contact_agent, nil, 'ticket.last_contact_agent verify - inbound')
-    assert_equal(ticket.first_response, nil, 'ticket.first_response verify - inbound')
-    assert_equal(ticket.close_time, nil, 'ticket.close_time verify - inbound')
+    assert_equal(ticket.last_contact_at.to_s, article_inbound.created_at.to_s, 'ticket.last_contact_at verify - inbound')
+    assert_equal(ticket.last_contact_customer_at.to_s, article_inbound.created_at.to_s, 'ticket.last_contact_customer_at verify - inbound')
+    assert_equal(ticket.last_contact_agent_at, nil, 'ticket.last_contact_agent_at verify - inbound')
+    assert_equal(ticket.first_response_at, nil, 'ticket.first_response_at verify - inbound')
+    assert_equal(ticket.close_at, nil, 'ticket.close_at verify - inbound')
 
     # create outbound article
     article_outbound = Ticket::Article.create!(
@@ -494,11 +494,11 @@ class TicketSlaTest < ActiveSupport::TestCase
     )
     ticket = Ticket.find(ticket.id)
     assert_equal(ticket.article_count, 3, 'ticket.article_count verify - inbound')
-    assert_equal(ticket.last_contact.to_s, article_outbound.created_at.to_s, 'ticket.last_contact verify - inbound')
-    assert_equal(ticket.last_contact_customer.to_s, article_inbound.created_at.to_s, 'ticket.last_contact_customer verify - inbound')
-    assert_equal(ticket.last_contact_agent.to_s, article_outbound.created_at.to_s, 'ticket.last_contact_agent verify - inbound')
-    assert_equal(ticket.first_response.to_s, article_outbound.created_at.to_s, 'ticket.first_response verify - inbound')
-    assert_equal(ticket.close_time, nil, 'ticket.close_time verify - inbound')
+    assert_equal(ticket.last_contact_at.to_s, article_outbound.created_at.to_s, 'ticket.last_contact_at verify - inbound')
+    assert_equal(ticket.last_contact_customer_at.to_s, article_inbound.created_at.to_s, 'ticket.last_contact_customer_at verify - inbound')
+    assert_equal(ticket.last_contact_agent_at.to_s, article_outbound.created_at.to_s, 'ticket.last_contact_agent_at verify - inbound')
+    assert_equal(ticket.first_response_at.to_s, article_outbound.created_at.to_s, 'ticket.first_response_at verify - inbound')
+    assert_equal(ticket.close_at, nil, 'ticket.close_at verify - inbound')
 
     delete = sla.destroy
     assert(delete, 'sla destroy')
@@ -527,7 +527,7 @@ class TicketSlaTest < ActiveSupport::TestCase
       created_by_id: 1,
     )
     assert(ticket, 'ticket created')
-    assert_equal(ticket.escalation_time, nil, 'ticket.escalation_time verify')
+    assert_equal(ticket.escalation_at, nil, 'ticket.escalation_at verify')
 
     # set sla's for timezone "Europe/Berlin" wintertime (+1), so UTC times are 7:00-16:00
     calendar = Calendar.create_or_update(
@@ -600,10 +600,10 @@ class TicketSlaTest < ActiveSupport::TestCase
     )
     Scheduler.worker(true)
     ticket = Ticket.find(ticket.id)
-    assert_equal(ticket.escalation_time.gmtime.to_s, '2013-03-21 11:30:00 UTC', 'ticket.escalation_time verify 1')
-    assert_equal(ticket.first_response_escal_date.gmtime.to_s, '2013-03-21 11:30:00 UTC', 'ticket.first_response_escal_date verify 1')
-    assert_equal(ticket.update_time_escal_date.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.update_time_escal_date verify 1')
-    assert_equal(ticket.close_time_escal_date.gmtime.to_s, '2013-03-21 13:30:00 UTC', 'ticket.close_time_escal_date verify 1')
+    assert_equal(ticket.escalation_at.gmtime.to_s, '2013-03-21 11:30:00 UTC', 'ticket.escalation_at verify 1')
+    assert_equal(ticket.first_response_escalation_at.gmtime.to_s, '2013-03-21 11:30:00 UTC', 'ticket.first_response_escalation_at verify 1')
+    assert_equal(ticket.update_escalation_at.gmtime.to_s, '2013-03-21 12:30:00 UTC', 'ticket.update_escalation_at verify 1')
+    assert_equal(ticket.close_escalation_at.gmtime.to_s, '2013-03-21 13:30:00 UTC', 'ticket.close_escalation_at verify 1')
 
     delete = sla.destroy
     assert(delete, 'sla destroy')
@@ -622,7 +622,7 @@ class TicketSlaTest < ActiveSupport::TestCase
       created_by_id: 1,
     )
     assert(ticket, 'ticket created')
-    assert_equal(ticket.escalation_time, nil, 'ticket.escalation_time verify')
+    assert_equal(ticket.escalation_at, nil, 'ticket.escalation_at verify')
 
     # set sla's for timezone "Europe/Berlin" summertime (+2), so UTC times are 6:00-15:00
     calendar = Calendar.create_or_update(
@@ -689,10 +689,10 @@ class TicketSlaTest < ActiveSupport::TestCase
     )
     Scheduler.worker(true)
     ticket = Ticket.find(ticket.id)
-    assert_equal(ticket.escalation_time.gmtime.to_s, '2013-10-21 11:30:00 UTC', 'ticket.escalation_time verify 1')
-    assert_equal(ticket.first_response_escal_date.gmtime.to_s, '2013-10-21 11:30:00 UTC', 'ticket.first_response_escal_date verify 1')
-    assert_equal(ticket.update_time_escal_date.gmtime.to_s, '2013-10-21 12:30:00 UTC', 'ticket.update_time_escal_date verify 1')
-    assert_equal(ticket.close_time_escal_date.gmtime.to_s, '2013-10-21 13:30:00 UTC', 'ticket.close_time_escal_date verify 1')
+    assert_equal(ticket.escalation_at.gmtime.to_s, '2013-10-21 11:30:00 UTC', 'ticket.escalation_at verify 1')
+    assert_equal(ticket.first_response_escalation_at.gmtime.to_s, '2013-10-21 11:30:00 UTC', 'ticket.first_response_escalation_at verify 1')
+    assert_equal(ticket.update_escalation_at.gmtime.to_s, '2013-10-21 12:30:00 UTC', 'ticket.update_escalation_at verify 1')
+    assert_equal(ticket.close_escalation_at.gmtime.to_s, '2013-10-21 13:30:00 UTC', 'ticket.close_escalation_at verify 1')
 
     delete = ticket.destroy
     assert(delete, 'ticket destroy')
@@ -712,7 +712,7 @@ class TicketSlaTest < ActiveSupport::TestCase
       created_by_id: 1,
     )
     assert(ticket, 'ticket created')
-    assert_equal(ticket.escalation_time, nil, 'ticket.escalation_time verify')
+    assert_equal(ticket.escalation_at, nil, 'ticket.escalation_at verify')
 
     # set sla's for timezone "Europe/Berlin" summertime (+2), so UTC times are 6:00-15:00
     sla = Sla.create_or_update(
@@ -727,10 +727,10 @@ class TicketSlaTest < ActiveSupport::TestCase
     )
     Scheduler.worker(true)
     ticket = Ticket.find(ticket.id)
-    assert_equal(ticket.escalation_time.gmtime.to_s, '2013-10-21 08:00:00 UTC', 'ticket.escalation_time verify 1')
-    assert_equal(ticket.first_response_escal_date.gmtime.to_s, '2013-10-21 08:00:00 UTC', 'ticket.first_response_escal_date verify 1')
-    assert_equal(ticket.update_time_escal_date.gmtime.to_s, '2013-10-21 09:00:00 UTC', 'ticket.update_time_escal_date verify 1')
-    assert_equal(ticket.close_time_escal_date.gmtime.to_s, '2013-10-21 10:00:00 UTC', 'ticket.close_time_escal_date verify 1')
+    assert_equal(ticket.escalation_at.gmtime.to_s, '2013-10-21 08:00:00 UTC', 'ticket.escalation_at verify 1')
+    assert_equal(ticket.first_response_escalation_at.gmtime.to_s, '2013-10-21 08:00:00 UTC', 'ticket.first_response_escalation_at verify 1')
+    assert_equal(ticket.update_escalation_at.gmtime.to_s, '2013-10-21 09:00:00 UTC', 'ticket.update_escalation_at verify 1')
+    assert_equal(ticket.close_escalation_at.gmtime.to_s, '2013-10-21 10:00:00 UTC', 'ticket.close_escalation_at verify 1')
 
     ticket = Ticket.create!(
       title: 'some title holiday test',
@@ -744,10 +744,10 @@ class TicketSlaTest < ActiveSupport::TestCase
       created_by_id: 1,
     )
     ticket = Ticket.find(ticket.id)
-    assert_equal(ticket.escalation_time.gmtime.to_s, '2015-09-23 07:30:00 UTC', 'ticket.escalation_time verify 1')
-    assert_equal(ticket.first_response_escal_date.gmtime.to_s, '2015-09-23 07:30:00 UTC', 'ticket.first_response_escal_date verify 1')
-    assert_equal(ticket.update_time_escal_date.gmtime.to_s, '2015-09-23 08:30:00 UTC', 'ticket.update_time_escal_date verify 1')
-    assert_equal(ticket.close_time_escal_date.gmtime.to_s, '2015-09-23 09:30:00 UTC', 'ticket.close_time_escal_date verify 1')
+    assert_equal(ticket.escalation_at.gmtime.to_s, '2015-09-23 07:30:00 UTC', 'ticket.escalation_at verify 1')
+    assert_equal(ticket.first_response_escalation_at.gmtime.to_s, '2015-09-23 07:30:00 UTC', 'ticket.first_response_escalation_at verify 1')
+    assert_equal(ticket.update_escalation_at.gmtime.to_s, '2015-09-23 08:30:00 UTC', 'ticket.update_escalation_at verify 1')
+    assert_equal(ticket.close_escalation_at.gmtime.to_s, '2015-09-23 09:30:00 UTC', 'ticket.close_escalation_at verify 1')
 
     delete = sla.destroy
     assert(delete, 'sla destroy')
@@ -889,8 +889,8 @@ class TicketSlaTest < ActiveSupport::TestCase
     )
     ticket1.escalation_calculation
     ticket1 = Ticket.find(ticket1.id)
-    assert_equal(ticket1.escalation_time.gmtime.to_s, '2013-06-04 11:45:00 UTC', 'ticket1.escalation_time verify 1')
-    assert_equal(ticket1.first_response_escal_date.gmtime.to_s, '2013-06-04 11:45:00 UTC', 'ticket1.first_response_escal_date verify 1')
+    assert_equal(ticket1.escalation_at.gmtime.to_s, '2013-06-04 11:45:00 UTC', 'ticket1.escalation_at verify 1')
+    assert_equal(ticket1.first_response_escalation_at.gmtime.to_s, '2013-06-04 11:45:00 UTC', 'ticket1.first_response_escalation_at verify 1')
     assert_equal(ticket1.first_response_in_min, nil, 'ticket1.first_response_in_min verify 3')
     assert_equal(ticket1.first_response_diff_in_min, nil, 'ticket1.first_response_diff_in_min verify 3')
 
@@ -938,8 +938,8 @@ class TicketSlaTest < ActiveSupport::TestCase
     )
     ticket2.escalation_calculation(true)
     ticket2 = Ticket.find(ticket2.id)
-    assert_equal(ticket2.escalation_time.gmtime.to_s, '2013-06-04 16:00:00 UTC', 'ticket2.escalation_time verify 1')
-    assert_equal(ticket2.first_response_escal_date.gmtime.to_s, '2013-06-04 16:00:00 UTC', 'ticket2.first_response_escal_date verify 1')
+    assert_equal(ticket2.escalation_at.gmtime.to_s, '2013-06-04 16:00:00 UTC', 'ticket2.escalation_at verify 1')
+    assert_equal(ticket2.first_response_escalation_at.gmtime.to_s, '2013-06-04 16:00:00 UTC', 'ticket2.first_response_escalation_at verify 1')
     assert_equal(ticket2.first_response_in_min, nil, 'ticket2.first_response_in_min verify 3')
     assert_equal(ticket2.first_response_diff_in_min, nil, 'ticket2.first_response_diff_in_min verify 3')
 
@@ -998,12 +998,12 @@ class TicketSlaTest < ActiveSupport::TestCase
 
     # set update time
     ticket.update_attributes(
-      last_contact_agent: '2013-06-04 10:15:00 UTC',
+      last_contact_agent_at: '2013-06-04 10:15:00 UTC',
     )
 
     # set first response time
     ticket.update_attributes(
-      first_response: '2013-06-04 10:45:00 UTC',
+      first_response_at: '2013-06-04 10:45:00 UTC',
     )
 
     # set ticket from 11:30 to closed
@@ -1022,7 +1022,7 @@ class TicketSlaTest < ActiveSupport::TestCase
     )
 
     ticket.update_attributes(
-      close_time: '2013-06-04 12:00:00 UTC',
+      close_at: '2013-06-04 12:00:00 UTC',
     )
 
     # set sla's for timezone "Europe/Berlin" summertime (+2), so UTC times are 7:00-16:00
@@ -1076,14 +1076,14 @@ class TicketSlaTest < ActiveSupport::TestCase
     )
     Scheduler.worker(true)
     ticket = Ticket.find(ticket.id)
-    assert_equal(ticket.escalation_time.gmtime.to_s, '2013-06-04 13:30:00 UTC', 'ticket.escalation_time verify 1')
-    assert_equal(ticket.first_response_escal_date.gmtime.to_s, '2013-06-04 11:30:00 UTC', 'ticket.first_response_escal_date verify 1')
+    assert_equal(ticket.escalation_at.gmtime.to_s, '2013-06-04 13:30:00 UTC', 'ticket.escalation_at verify 1')
+    assert_equal(ticket.first_response_escalation_at.gmtime.to_s, '2013-06-04 11:30:00 UTC', 'ticket.first_response_escalation_at verify 1')
     assert_equal(ticket.first_response_in_min, 75, 'ticket.first_response_in_min verify 3')
     assert_equal(ticket.first_response_diff_in_min, 45, 'ticket.first_response_diff_in_min verify 3')
-    assert_equal(ticket.update_time_escal_date.gmtime.to_s, '2013-06-04 13:30:00 UTC', 'ticket.update_time_escal_date verify 1')
-    assert_equal(ticket.close_time_escal_date.gmtime.to_s, '2013-06-04 13:40:00 UTC', 'ticket.close_time_escal_date verify 1')
-    assert_equal(ticket.close_time_in_min, 150, 'ticket.close_time_in_min verify 3')
-    assert_equal(ticket.close_time_diff_in_min, 100, 'ticket.close_time_diff_in_min# verify 3')
+    assert_equal(ticket.update_escalation_at.gmtime.to_s, '2013-06-04 13:30:00 UTC', 'ticket.update_escalation_at verify 1')
+    assert_equal(ticket.close_escalation_at.gmtime.to_s, '2013-06-04 13:40:00 UTC', 'ticket.close_escalation_at verify 1')
+    assert_equal(ticket.close_in_min, 150, 'ticket.close_in_min verify 3')
+    assert_equal(ticket.close_diff_in_min, 100, 'ticket.close_diff_in_min# verify 3')
     delete = sla.destroy
     assert(delete, 'sla destroy')
 
@@ -1119,7 +1119,7 @@ class TicketSlaTest < ActiveSupport::TestCase
       updated_at: '2013-06-04 12:00:00 UTC',
     )
     ticket.update_attributes(
-      close_time: '2013-06-04 12:00:00 UTC',
+      close_at: '2013-06-04 12:00:00 UTC',
     )
     ticket.escalation_calculation(true)
 
@@ -1173,14 +1173,14 @@ class TicketSlaTest < ActiveSupport::TestCase
     )
     Scheduler.worker(true)
     ticket = Ticket.find(ticket.id)
-    assert_equal(ticket.escalation_time, nil, 'ticket.escalation_time verify 1')
-    assert_equal(ticket.first_response_escal_date.gmtime.to_s, '2013-06-04 14:00:00 UTC', 'ticket.first_response_escal_date verify 1')
+    assert_equal(ticket.escalation_at, nil, 'ticket.escalation_at verify 1')
+    assert_equal(ticket.first_response_escalation_at.gmtime.to_s, '2013-06-04 14:00:00 UTC', 'ticket.first_response_escalation_at verify 1')
     assert_equal(ticket.first_response_in_min, nil, 'ticket.first_response_in_min verify 3')
     assert_equal(ticket.first_response_diff_in_min, nil, 'ticket.first_response_diff_in_min verify 3')
-    assert_equal(ticket.update_time_escal_date.gmtime.to_s, '2013-06-04 15:00:00 UTC', 'ticket.update_time_escal_date verify 1')
-    assert_equal(ticket.close_time_escal_date.gmtime.to_s, '2013-06-04 16:00:00 UTC', 'ticket.close_time_escal_date verify 1')
-    assert_equal(ticket.close_time_in_min, 0, 'ticket.close_time_in_min verify 3')
-    assert_equal(ticket.close_time_diff_in_min, 240, 'ticket.close_time_diff_in_min# verify 3')
+    assert_equal(ticket.update_escalation_at.gmtime.to_s, '2013-06-04 15:00:00 UTC', 'ticket.update_escalation_at verify 1')
+    assert_equal(ticket.close_escalation_at.gmtime.to_s, '2013-06-04 16:00:00 UTC', 'ticket.close_escalation_at verify 1')
+    assert_equal(ticket.close_in_min, 0, 'ticket.close_in_min verify 3')
+    assert_equal(ticket.close_diff_in_min, 240, 'ticket.close_diff_in_min# verify 3')
 
     delete = sla.destroy
     assert(delete, 'sla destroy')
@@ -1247,7 +1247,7 @@ class TicketSlaTest < ActiveSupport::TestCase
       updated_at: '2013-06-04 12:00:00 UTC',
     )
     ticket.update_attributes(
-      close_time: '2013-06-04 12:00:00 UTC',
+      close_at: '2013-06-04 12:00:00 UTC',
     )
 
     calendar = Calendar.create_or_update(
@@ -1300,14 +1300,14 @@ class TicketSlaTest < ActiveSupport::TestCase
     )
     Scheduler.worker(true)
     ticket = Ticket.find(ticket.id)
-    assert_equal(ticket.escalation_time, nil, 'ticket.escalation_time verify 1')
-    assert_equal(ticket.first_response_escal_date.gmtime.to_s, '2013-06-04 13:30:00 UTC', 'ticket.first_response_escal_date verify 1')
+    assert_equal(ticket.escalation_at, nil, 'ticket.escalation_at verify 1')
+    assert_equal(ticket.first_response_escalation_at.gmtime.to_s, '2013-06-04 13:30:00 UTC', 'ticket.first_response_escalation_at verify 1')
     assert_equal(ticket.first_response_in_min, nil, 'ticket.first_response_in_min verify 3')
     assert_equal(ticket.first_response_diff_in_min, nil, 'ticket.first_response_diff_in_min verify 3')
-    assert_equal(ticket.update_time_escal_date.gmtime.to_s, '2013-06-04 14:30:00 UTC', 'ticket.update_time_escal_date verify 1')
-    assert_equal(ticket.close_time_escal_date.gmtime.to_s, '2013-06-04 15:30:00 UTC', 'ticket.close_time_escal_date verify 1')
-    assert_equal(ticket.close_time_in_min, 30, 'ticket.close_time_in_min verify 3')
-    assert_equal(ticket.close_time_diff_in_min, 210, 'ticket.close_time_diff_in_min# verify 3')
+    assert_equal(ticket.update_escalation_at.gmtime.to_s, '2013-06-04 14:30:00 UTC', 'ticket.update_escalation_at verify 1')
+    assert_equal(ticket.close_escalation_at.gmtime.to_s, '2013-06-04 15:30:00 UTC', 'ticket.close_escalation_at verify 1')
+    assert_equal(ticket.close_in_min, 30, 'ticket.close_in_min verify 3')
+    assert_equal(ticket.close_diff_in_min, 210, 'ticket.close_diff_in_min# verify 3')
 
     delete = sla.destroy
     assert(delete, 'sla destroy')
@@ -1390,7 +1390,7 @@ class TicketSlaTest < ActiveSupport::TestCase
       updated_at: '2013-06-04 12:00:00 UTC',
     )
     ticket.update_attributes(
-      close_time: '2013-06-04 12:00:00 UTC',
+      close_at: '2013-06-04 12:00:00 UTC',
     )
 
     calendar = Calendar.create_or_update(
@@ -1443,14 +1443,14 @@ class TicketSlaTest < ActiveSupport::TestCase
     )
     Scheduler.worker(true)
     ticket = Ticket.find(ticket.id)
-    assert_equal(ticket.escalation_time, nil, 'ticket.escalation_time verify 1')
-    assert_equal(ticket.first_response_escal_date.gmtime.to_s, '2013-06-04 13:00:00 UTC', 'ticket.first_response_escal_date verify 1')
+    assert_equal(ticket.escalation_at, nil, 'ticket.escalation_at verify 1')
+    assert_equal(ticket.first_response_escalation_at.gmtime.to_s, '2013-06-04 13:00:00 UTC', 'ticket.first_response_escalation_at verify 1')
     assert_equal(ticket.first_response_in_min, nil, 'ticket.first_response_in_min verify 3')
     assert_equal(ticket.first_response_diff_in_min, nil, 'ticket.first_response_diff_in_min verify 3')
-    assert_equal(ticket.update_time_escal_date.gmtime.to_s, '2013-06-04 14:00:00 UTC', 'ticket.update_time_escal_date verify 1')
-    assert_equal(ticket.close_time_escal_date.gmtime.to_s, '2013-06-04 15:00:00 UTC', 'ticket.close_time_escal_date verify 1')
-    assert_equal(ticket.close_time_in_min, 60, 'ticket.close_time_in_min verify 3')
-    assert_equal(ticket.close_time_diff_in_min, 180, 'ticket.close_time_diff_in_min# verify 3')
+    assert_equal(ticket.update_escalation_at.gmtime.to_s, '2013-06-04 14:00:00 UTC', 'ticket.update_escalation_at verify 1')
+    assert_equal(ticket.close_escalation_at.gmtime.to_s, '2013-06-04 15:00:00 UTC', 'ticket.close_escalation_at verify 1')
+    assert_equal(ticket.close_in_min, 60, 'ticket.close_in_min verify 3')
+    assert_equal(ticket.close_diff_in_min, 180, 'ticket.close_diff_in_min# verify 3')
 
     delete = sla.destroy
     assert(delete, 'sla destroy')
diff --git a/test/unit/ticket_test.rb b/test/unit/ticket_test.rb
index 27247b253..f9012db71 100644
--- a/test/unit/ticket_test.rb
+++ b/test/unit/ticket_test.rb
@@ -36,11 +36,11 @@ class TicketTest < ActiveSupport::TestCase
 
     ticket = Ticket.find(ticket.id)
     assert_equal(ticket.article_count, 1, 'ticket.article_count verify - inbound')
-    assert_equal(ticket.last_contact.to_s, article_inbound1.created_at.to_s, 'ticket.last_contact verify - inbound')
-    assert_equal(ticket.last_contact_customer.to_s, article_inbound1.created_at.to_s, 'ticket.last_contact_customer verify - inbound')
-    assert_equal(ticket.last_contact_agent, nil, 'ticket.last_contact_agent verify - inbound')
-    assert_equal(ticket.first_response, nil, 'ticket.first_response verify - inbound')
-    assert_equal(ticket.close_time, nil, 'ticket.close_time verify - inbound')
+    assert_equal(ticket.last_contact_at.to_s, article_inbound1.created_at.to_s, 'ticket.last_contact verify - inbound')
+    assert_equal(ticket.last_contact_customer_at.to_s, article_inbound1.created_at.to_s, 'ticket.last_contact_customer_at verify - inbound')
+    assert_equal(ticket.last_contact_agent_at, nil, 'ticket.last_contact_agent_at verify - inbound')
+    assert_equal(ticket.first_response_at, nil, 'ticket.first_response_at verify - inbound')
+    assert_equal(ticket.close_at, nil, 'ticket.close_at verify - inbound')
 
     # create inbound article #2
     sleep 2
@@ -61,11 +61,11 @@ class TicketTest < ActiveSupport::TestCase
 
     ticket = Ticket.find(ticket.id)
     assert_equal(ticket.article_count, 2, 'ticket.article_count verify - inbound')
-    assert_equal(ticket.last_contact.to_s, article_inbound1.created_at.to_s, 'ticket.last_contact verify - inbound')
-    assert_equal(ticket.last_contact_customer.to_s, article_inbound1.created_at.to_s, 'ticket.last_contact_customer verify - inbound')
-    assert_equal(ticket.last_contact_agent, nil, 'ticket.last_contact_agent verify - inbound')
-    assert_equal(ticket.first_response, nil, 'ticket.first_response verify - inbound')
-    assert_equal(ticket.close_time, nil, 'ticket.close_time verify - inbound')
+    assert_equal(ticket.last_contact_at.to_s, article_inbound1.created_at.to_s, 'ticket.last_contact verify - inbound')
+    assert_equal(ticket.last_contact_customer_at.to_s, article_inbound1.created_at.to_s, 'ticket.last_contact_customer_at verify - inbound')
+    assert_equal(ticket.last_contact_agent_at, nil, 'ticket.last_contact_agent_at verify - inbound')
+    assert_equal(ticket.first_response_at, nil, 'ticket.first_response_at verify - inbound')
+    assert_equal(ticket.close_at, nil, 'ticket.close_at verify - inbound')
 
     # create note article
     article_note = Ticket::Article.create(
@@ -84,11 +84,11 @@ class TicketTest < ActiveSupport::TestCase
 
     ticket = Ticket.find(ticket.id)
     assert_equal(ticket.article_count, 3, 'ticket.article_count verify - note')
-    assert_equal(ticket.last_contact.to_s, article_inbound1.created_at.to_s, 'ticket.last_contact verify - note')
-    assert_equal(ticket.last_contact_customer.to_s, article_inbound1.created_at.to_s, 'ticket.last_contact_customer verify - note')
-    assert_equal(ticket.last_contact_agent, nil, 'ticket.last_contact_agent verify - note')
-    assert_equal(ticket.first_response, nil, 'ticket.first_response verify - note')
-    assert_equal(ticket.close_time, nil, 'ticket.close_time verify - note')
+    assert_equal(ticket.last_contact_at.to_s, article_inbound1.created_at.to_s, 'ticket.last_contact verify - note')
+    assert_equal(ticket.last_contact_customer_at.to_s, article_inbound1.created_at.to_s, 'ticket.last_contact_customer_at verify - note')
+    assert_equal(ticket.last_contact_agent_at, nil, 'ticket.last_contact_agent_at verify - note')
+    assert_equal(ticket.first_response_at, nil, 'ticket.first_response_at verify - note')
+    assert_equal(ticket.close_at, nil, 'ticket.close_at verify - note')
 
     # create outbound article
     sleep 2
@@ -108,11 +108,11 @@ class TicketTest < ActiveSupport::TestCase
 
     ticket = Ticket.find(ticket.id)
     assert_equal(ticket.article_count, 4, 'ticket.article_count verify - outbound')
-    assert_equal(ticket.last_contact.to_s, article_outbound.created_at.to_s, 'ticket.last_contact verify - outbound')
-    assert_equal(ticket.last_contact_customer.to_s, article_inbound1.created_at.to_s, 'ticket.last_contact_customer verify - outbound')
-    assert_equal(ticket.last_contact_agent.to_s, article_outbound.created_at.to_s, 'ticket.last_contact_agent verify - outbound')
-    assert_equal(ticket.first_response.to_s, article_outbound.created_at.to_s, 'ticket.first_response verify - outbound')
-    assert_equal(ticket.close_time, nil, 'ticket.close_time verify - outbound')
+    assert_equal(ticket.last_contact_at.to_s, article_outbound.created_at.to_s, 'ticket.last_contact verify - outbound')
+    assert_equal(ticket.last_contact_customer_at.to_s, article_inbound1.created_at.to_s, 'ticket.last_contact_customer_at verify - outbound')
+    assert_equal(ticket.last_contact_agent_at.to_s, article_outbound.created_at.to_s, 'ticket.last_contact_agent_at verify - outbound')
+    assert_equal(ticket.first_response_at.to_s, article_outbound.created_at.to_s, 'ticket.first_response_at verify - outbound')
+    assert_equal(ticket.close_at, nil, 'ticket.close_at verify - outbound')
 
     # create inbound article #3
     article_inbound3 = Ticket::Article.create(
@@ -132,11 +132,11 @@ class TicketTest < ActiveSupport::TestCase
 
     ticket = Ticket.find(ticket.id)
     assert_equal(ticket.article_count, 5, 'ticket.article_count verify - inbound')
-    assert_equal(ticket.last_contact.to_s, article_inbound3.created_at.to_s, 'ticket.last_contact verify - inbound')
-    assert_equal(ticket.last_contact_customer.to_s, article_inbound3.created_at.to_s, 'ticket.last_contact_customer verify - inbound')
-    assert_equal(ticket.last_contact_agent.to_s, article_outbound.created_at.to_s, 'ticket.last_contact_agent verify - outbound')
-    assert_equal(ticket.first_response.to_s, article_outbound.created_at.to_s, 'ticket.first_response verify - outbound')
-    assert_equal(ticket.close_time, nil, 'ticket.close_time verify - outbound')
+    assert_equal(ticket.last_contact_at.to_s, article_inbound3.created_at.to_s, 'ticket.last_contact verify - inbound')
+    assert_equal(ticket.last_contact_customer_at.to_s, article_inbound3.created_at.to_s, 'ticket.last_contact_customer_at verify - inbound')
+    assert_equal(ticket.last_contact_agent_at.to_s, article_outbound.created_at.to_s, 'ticket.last_contact_agent_at verify - outbound')
+    assert_equal(ticket.first_response_at.to_s, article_outbound.created_at.to_s, 'ticket.first_response_at verify - outbound')
+    assert_equal(ticket.close_at, nil, 'ticket.close_at verify - outbound')
 
     # create inbound article #4
     sleep 2
@@ -157,22 +157,22 @@ class TicketTest < ActiveSupport::TestCase
 
     ticket = Ticket.find(ticket.id)
     assert_equal(ticket.article_count, 6, 'ticket.article_count verify - inbound')
-    assert_equal(ticket.last_contact.to_s, article_inbound3.created_at.to_s, 'ticket.last_contact verify - inbound')
-    assert_equal(ticket.last_contact_customer.to_s, article_inbound3.created_at.to_s, 'ticket.last_contact_customer verify - inbound')
-    assert_equal(ticket.last_contact_agent.to_s, article_outbound.created_at.to_s, 'ticket.last_contact_agent verify - outbound')
-    assert_equal(ticket.first_response.to_s, article_outbound.created_at.to_s, 'ticket.first_response verify - outbound')
-    assert_equal(ticket.close_time, nil, 'ticket.close_time verify - outbound')
+    assert_equal(ticket.last_contact_at.to_s, article_inbound3.created_at.to_s, 'ticket.last_contact verify - inbound')
+    assert_equal(ticket.last_contact_customer_at.to_s, article_inbound3.created_at.to_s, 'ticket.last_contact_customer_at verify - inbound')
+    assert_equal(ticket.last_contact_agent_at.to_s, article_outbound.created_at.to_s, 'ticket.last_contact_agent_at verify - outbound')
+    assert_equal(ticket.first_response_at.to_s, article_outbound.created_at.to_s, 'ticket.first_response_at verify - outbound')
+    assert_equal(ticket.close_at, nil, 'ticket.close_at verify - outbound')
 
     ticket.state_id = Ticket::State.where(name: 'closed').first.id
     ticket.save
 
     ticket = Ticket.find(ticket.id)
     assert_equal(ticket.article_count, 6, 'ticket.article_count verify - state update')
-    assert_equal(ticket.last_contact.to_s, article_inbound3.created_at.to_s, 'ticket.last_contact verify - state update')
-    assert_equal(ticket.last_contact_customer.to_s, article_inbound3.created_at.to_s, 'ticket.last_contact_customer verify - state update')
-    assert_equal(ticket.last_contact_agent.to_s, article_outbound.created_at.to_s, 'ticket.last_contact_agent verify - state update')
-    assert_equal(ticket.first_response.to_s, article_outbound.created_at.to_s, 'ticket.first_response verify - state update')
-    assert(ticket.close_time, 'ticket.close_time verify - state update')
+    assert_equal(ticket.last_contact_at.to_s, article_inbound3.created_at.to_s, 'ticket.last_contact verify - state update')
+    assert_equal(ticket.last_contact_customer_at.to_s, article_inbound3.created_at.to_s, 'ticket.last_contact_customer_at verify - state update')
+    assert_equal(ticket.last_contact_agent_at.to_s, article_outbound.created_at.to_s, 'ticket.last_contact_agent_at verify - state update')
+    assert_equal(ticket.first_response_at.to_s, article_outbound.created_at.to_s, 'ticket.first_response_at verify - state update')
+    assert(ticket.close_at, 'ticket.close_at verify - state update')
 
     # set pending time
     ticket.state_id     = Ticket::State.find_by(name: 'pending reminder').id