diff --git a/lib/calendar_subscriptions.rb b/lib/calendar_subscriptions.rb
index 0d74c8794..1b7b37a9b 100644
--- a/lib/calendar_subscriptions.rb
+++ b/lib/calendar_subscriptions.rb
@@ -5,6 +5,7 @@ class CalendarSubscriptions
   def initialize(user)
     @user        = user
     @preferences = {}
+    @time_zone   = Setting.get('timezone_default').presence || 'UTC'
 
     default_preferences = Setting.where(area: 'Defaults::CalendarSubscriptions')
     default_preferences.each do |calendar_subscription|
@@ -42,7 +43,7 @@ class CalendarSubscriptions
     if @preferences[ object_name ].present?
       sub_class_name = object_name.to_s.capitalize
       object         = "CalendarSubscriptions::#{sub_class_name}".constantize
-      instance       = object.new(@user, @preferences[ object_name ])
+      instance       = object.new(@user, @preferences[ object_name ], @time_zone)
       method         = instance.method(method_name)
       events_data += method.call
     end
@@ -56,8 +57,8 @@ class CalendarSubscriptions
     events_data.each do |event_data|
 
       cal.event do |e|
-        e.dtstart = Icalendar::Values::DateTime.new(event_data[:dtstart], 'tzid' => 'UTC')
-        e.dtend   = Icalendar::Values::DateTime.new(event_data[:dtend], 'tzid' => 'UTC')
+        e.dtstart = Icalendar::Values::DateTime.new(event_data[:dtstart], 'tzid' => @time_zone)
+        e.dtend   = Icalendar::Values::DateTime.new(event_data[:dtend], 'tzid' => @time_zone)
         if event_data[:alarm]
           e.alarm do |a|
             a.action  = 'DISPLAY'
diff --git a/lib/calendar_subscriptions/tickets.rb b/lib/calendar_subscriptions/tickets.rb
index c19c41649..43150bd90 100644
--- a/lib/calendar_subscriptions/tickets.rb
+++ b/lib/calendar_subscriptions/tickets.rb
@@ -2,10 +2,10 @@
 
 class CalendarSubscriptions::Tickets
 
-  def initialize(user, preferences)
+  def initialize(user, preferences, time_zone)
     @user        = user
     @preferences = preferences
-    @tzid        = 'UTC'
+    @time_zone   = time_zone
   end
 
   def all
@@ -86,8 +86,8 @@ class CalendarSubscriptions::Tickets
 
       translated_state = Translation.translate(user_locale, ticket.state.name)
 
-      event_data[:dtstart]     = Icalendar::Values::Date.new(Time.zone.today, 'tzid' => @tzid)
-      event_data[:dtend]       = Icalendar::Values::Date.new(Time.zone.today, 'tzid' => @tzid)
+      event_data[:dtstart]     = Icalendar::Values::Date.new(Time.zone.today, 'tzid' => @time_zone)
+      event_data[:dtend]       = Icalendar::Values::Date.new(Time.zone.today, 'tzid' => @time_zone)
       event_data[:summary]     = "#{translated_state} #{translated_ticket}: '#{ticket.title}'"
       event_data[:description] = "T##{ticket.number}"
 
@@ -144,8 +144,8 @@ class CalendarSubscriptions::Tickets
 
       translated_state = Translation.translate(user_locale, ticket.state.name)
 
-      event_data[:dtstart]     = Icalendar::Values::DateTime.new(pending_time, 'tzid' => @tzid)
-      event_data[:dtend]       = Icalendar::Values::DateTime.new(pending_time, 'tzid' => @tzid)
+      event_data[:dtstart]     = Icalendar::Values::DateTime.new(pending_time, 'tzid' => @time_zone)
+      event_data[:dtend]       = Icalendar::Values::DateTime.new(pending_time, 'tzid' => @time_zone)
       event_data[:summary]     = "#{translated_state} #{translated_ticket}: '#{ticket.title}' #{customer}: #{ticket.customer.longname}"
       event_data[:description] = "T##{ticket.number}"
       if alarm?
@@ -198,8 +198,8 @@ class CalendarSubscriptions::Tickets
         escalation_at = Time.zone.today
       end
 
-      event_data[:dtstart]     = Icalendar::Values::DateTime.new(escalation_at, 'tzid' => @tzid)
-      event_data[:dtend]       = Icalendar::Values::DateTime.new(escalation_at, 'tzid' => @tzid)
+      event_data[:dtstart]     = Icalendar::Values::DateTime.new(escalation_at, 'tzid' => @time_zone)
+      event_data[:dtend]       = Icalendar::Values::DateTime.new(escalation_at, 'tzid' => @time_zone)
       event_data[:summary]     = "#{translated_ticket_escalation}: '#{ticket.title}' #{customer}: #{ticket.customer.longname}"
       event_data[:description] = "T##{ticket.number}"
       if alarm?
diff --git a/spec/requests/calendar_subscriptions_spec.rb b/spec/requests/calendar_subscriptions_spec.rb
index cf97b0c51..e8b1923cc 100644
--- a/spec/requests/calendar_subscriptions_spec.rb
+++ b/spec/requests/calendar_subscriptions_spec.rb
@@ -10,4 +10,29 @@ RSpec.describe 'iCal endpoints', type: :request do
       expect(response.body).to eq("HTTP Basic: Access denied.\n")
     end
   end
+
+  describe 'time zone', authenticated_as: :user do
+    let(:group) { create(:group) }
+    let(:user) { create(:agent) }
+
+    before do
+      user.groups << group
+
+      create(:ticket, group: group, owner: user, state_name: 'open', pending_time: 1.day.ago)
+    end
+
+    it 'returns zero offset time if no time zone set' do
+      get '/ical/tickets'
+
+      expect(response.body).to match %r{DTSTART:\d{8}T0{6}Z}
+    end
+
+    it 'returns selected time zone' do
+      Setting.set 'timezone_default', 'Europe/Vilnius'
+
+      get '/ical/tickets'
+
+      expect(response.body).to match %r{DTSTART;TZID=Europe/Vilnius:\d{8}T0{6}}
+    end
+  end
 end