Centralizes time formatting with timezone support

Addresses inconsistent time formatting and lack of timezone
handling throughout the application by introducing a
`TimeFormatter` utility.

This class centralizes time formatting logic, providing
timezone conversion (defaults to Europe/Copenhagen) and
support for both 12-hour and 24-hour formats, configurable
via `CalendarConfig`.

It also updates event rendering to utilize the new
`TimeFormatter` for consistent time displays.

src/core/CalendarConfig.ts

@@ -3,6 +3,7 @@
 import { eventBus } from './EventBus';
 import { CoreEvents } from '../constants/CoreEvents';
 import { CalendarConfig as ICalendarConfig, ViewPeriod, CalendarMode } from '../types/CalendarTypes';
+import { TimeFormatter, TimeFormatSettings } from '../utils/TimeFormatter';
 
 /**
  * All-day event layout constants
@@ -69,6 +70,15 @@ interface ResourceViewSettings {
   showAllDay: boolean;          // Show all-day event row
 }
 
+/**
+ * Time format configuration settings
+ */
+interface TimeFormatConfig {
+  timezone: string;
+  use24HourFormat: boolean;
+  locale: string;
+}
+
 /**
  * Calendar configuration management
  */
@@ -80,6 +90,7 @@ export class CalendarConfig {
   private dateViewSettings: DateViewSettings;
   private resourceViewSettings: ResourceViewSettings;
   private currentWorkWeek: string = 'standard';
+  private timeFormatConfig: TimeFormatConfig;
 
   constructor() {
     this.config = {
@@ -142,9 +153,19 @@ export class CalendarConfig {
       showAllDay: true
     };
 
+    // Time format settings - default to Denmark
+    this.timeFormatConfig = {
+      timezone: 'Europe/Copenhagen',
+      use24HourFormat: true,
+      locale: 'da-DK'
+    };
+
     // Set computed values
     this.config.minEventDuration = this.gridSettings.snapInterval;
     
+    // Initialize TimeFormatter with default settings
+    TimeFormatter.configure(this.timeFormatConfig);
+    
     // Load calendar type from URL parameter
     this.loadCalendarType();
     
@@ -472,6 +493,57 @@ export class CalendarConfig {
     return this.currentWorkWeek;
   }
 
+  /**
+   * Get time format settings
+   */
+  getTimeFormatSettings(): TimeFormatConfig {
+    return { ...this.timeFormatConfig };
+  }
+
+  /**
+   * Update time format settings
+   */
+  updateTimeFormatSettings(updates: Partial<TimeFormatConfig>): void {
+    this.timeFormatConfig = { ...this.timeFormatConfig, ...updates };
+    
+    // Update TimeFormatter with new settings
+    TimeFormatter.configure(this.timeFormatConfig);
+    
+    // Emit time format change event
+    eventBus.emit(CoreEvents.REFRESH_REQUESTED, {
+      key: 'timeFormatSettings',
+      value: this.timeFormatConfig
+    });
+  }
+
+  /**
+   * Set timezone (convenience method)
+   */
+  setTimezone(timezone: string): void {
+    this.updateTimeFormatSettings({ timezone });
+  }
+
+  /**
+   * Set 12/24 hour format (convenience method)
+   */
+  set24HourFormat(use24Hour: boolean): void {
+    this.updateTimeFormatSettings({ use24HourFormat: use24Hour });
+  }
+
+  /**
+   * Get configured timezone
+   */
+  getTimezone(): string {
+    return this.timeFormatConfig.timezone;
+  }
+
+  /**
+   * Check if using 24-hour format
+   */
+  is24HourFormat(): boolean {
+    return this.timeFormatConfig.use24HourFormat;
+  }
+
 }
 
 // Create singleton instance