Remove some redundant code.

app/components/users/non_working_times/calendar_component.rb

@@ -74,10 +74,11 @@ module Users
       end
 
       def user_events
+        system_dates = non_working_times.grep(NonWorkingDay).to_set(&:date)
         non_working_times
           .grep(UserNonWorkingTime)
           .map do |nwt|
-            clipped = nwt.clip_to_year(year)
+            clipped = nwt.clip_to_year(year, system_non_working_dates: system_dates)
             {
               start: clipped.start_date.iso8601,
               end: (clipped.end_date + 1.day).iso8601,

app/components/users/non_working_times/sidebar_component.rb

@@ -40,10 +40,11 @@ module Users
       private
 
       def user_non_working_times
+        system_dates = non_working_times.grep(NonWorkingDay).to_set(&:date)
         non_working_times
           .grep(UserNonWorkingTime)
           .sort_by(&:start_date)
-          .map { |nwt| nwt.clip_to_year(year) }
+          .map { |nwt| nwt.clip_to_year(year, system_non_working_dates: system_dates) }
       end
 
       def global_day_count

app/contracts/user_non_working_times/base_contract.rb

@@ -46,14 +46,7 @@ module UserNonWorkingTimes
     private
 
     def validate_manage_permission
-      unless can_manage_working_times?
-        errors.add :base, :error_unauthorized
-      end
-    end
-
-    def can_manage_working_times?
-      user.allowed_globally?(:manage_working_times) ||
-        (model.user_id == user.id && user.allowed_globally?(:manage_own_working_times))
+      errors.add(:base, :error_unauthorized) unless self.class.can_manage?(user:, target_user: model.user)
     end
   end
 end

app/contracts/user_non_working_times/delete_contract.rb

@@ -30,10 +30,7 @@
 
 module UserNonWorkingTimes
   class DeleteContract < ::DeleteContract
-    delete_permission -> {
-      user.allowed_globally?(:manage_working_times) ||
-        (model.user_id == user.id && user.allowed_globally?(:manage_own_working_times))
-    }
+    delete_permission -> { BaseContract.can_manage?(user:, target_user: model.user) }
 
     def self.can_delete?(user:, target_user:)
       BaseContract.can_manage?(user:, target_user:)

app/models/user_non_working_time.rb

@@ -77,7 +77,7 @@ class UserNonWorkingTime < ApplicationRecord
 
   delegate :count, to: :working_days, prefix: true
 
-  def clip_to_year(year)
+  def clip_to_year(year, system_non_working_dates: nil)
     year_start = Date.new(year, 1, 1)
     year_end   = Date.new(year, 12, 31)
 
@@ -88,7 +88,7 @@ class UserNonWorkingTime < ApplicationRecord
       non_working_time: self,
       start_date: clipped_start,
       end_date: clipped_end,
-      working_days_count: working_days_in(clipped_start..clipped_end).count,
+      working_days_count: working_days_in(clipped_start..clipped_end, system_non_working_dates:).count,
       continues_from_previous_year: start_date < year_start,
       continues_into_next_year: end_date > year_end
     )
@@ -96,9 +96,9 @@ class UserNonWorkingTime < ApplicationRecord
 
   private
 
-  def working_days_in(date_range)
+  def working_days_in(date_range, system_non_working_dates: nil)
     working_wdays = Setting.working_days.map { |d| d % 7 }
-    system_wide = NonWorkingDay.where(date: date_range).pluck(:date).to_set
+    system_wide = system_non_working_dates || NonWorkingDay.where(date: date_range).pluck(:date).to_set
     date_range.select { |date| working_wdays.include?(date.wday) && system_wide.exclude?(date) }
   end