Corrected with rubocop cop 'Style/FormatString'.

app/models/scheduler.rb

@@ -116,7 +116,7 @@ class Scheduler < ApplicationModel
         sleep(wait)
         logger.info '*** worker loop'
       else
-        printf "*** #{count} jobs processed at %.4f j/s, %d failed ...\n" % [count / realtime, result.last]
+        format "*** #{count} jobs processed at %.4f j/s, %d failed ...\n", count / realtime, result.last
       end
     end
   end

app/models/ticket/number/date.rb

@@ -33,7 +33,7 @@ module Ticket::Number::Date
     end
 
     system_id = Setting.get('system_id') || ''
-    number = t.strftime('%Y%m%d') + system_id.to_s + sprintf( '%04d', counter_increment)
+    number = t.strftime('%Y%m%d') + system_id.to_s + format('%04d', counter_increment)
 
     # calculate a checksum
     # The algorithm to calculate the checksum is derived from the one