Adds technical date and time formatting

Adds options for technical date and time formatting and includes the option to show seconds.

Updates time formatting to use UTC-to-local conversion and ensures consistent colon separators for time values.

Adjusts all-day event handling to preserve original start/end times.

src/utils/TimeFormatter.ts

@@ -11,13 +11,17 @@ export interface TimeFormatSettings {
   timezone: string;
   use24HourFormat: boolean;
   locale: string;
+  dateFormat: 'locale' | 'technical';
+  showSeconds: boolean;
 }
 
 export class TimeFormatter {
   private static settings: TimeFormatSettings = {
     timezone: 'Europe/Copenhagen',  // Default to Denmark
     use24HourFormat: true,          // 24-hour format standard in Denmark
-    locale: 'da-DK'                 // Danish locale
+    locale: 'da-DK',                // Danish locale
+    dateFormat: 'technical',        // Use technical format yyyy-mm-dd hh:mm:ss
+    showSeconds: false              // Don't show seconds by default
   };
 
   /**
@@ -88,12 +92,10 @@ export class TimeFormatter {
   static format24Hour(date: Date): string {
     const localDate = TimeFormatter.convertToLocalTime(date);
     
-    return localDate.toLocaleTimeString(TimeFormatter.settings.locale, {
-      timeZone: TimeFormatter.settings.timezone,
-      hour: '2-digit',
-      minute: '2-digit',
-      hour12: false
-    });
+    // Always use colon separator, not locale-specific formatting
+    let hours = String(localDate.getHours()).padStart(2, '0');
+    let minutes = String(localDate.getMinutes()).padStart(2, '0');
+    return `${hours}:${minutes}`;
   }
 
   /**
@@ -184,4 +186,38 @@ export class TimeFormatter {
     }).split(' ').pop() || '';
   }
 
+  /**
+   * Format date in technical format: yyyy-mm-dd
+   */
+  static formatDateTechnical(date: Date): string {
+    let year = date.getFullYear();
+    let month = String(date.getMonth() + 1).padStart(2, '0');
+    let day = String(date.getDate()).padStart(2, '0');
+    return `${year}-${month}-${day}`;
+  }
+
+  /**
+   * Format time in technical format: hh:mm or hh:mm:ss
+   */
+  static formatTimeTechnical(date: Date, includeSeconds: boolean = false): string {
+    let hours = String(date.getHours()).padStart(2, '0');
+    let minutes = String(date.getMinutes()).padStart(2, '0');
+    
+    if (includeSeconds) {
+      let seconds = String(date.getSeconds()).padStart(2, '0');
+      return `${hours}:${minutes}:${seconds}`;
+    }
+    return `${hours}:${minutes}`;
+  }
+
+  /**
+   * Format date and time in technical format: yyyy-mm-dd hh:mm:ss
+   */
+  static formatDateTimeTechnical(date: Date): string {
+    let localDate = TimeFormatter.convertToLocalTime(date);
+    let dateStr = TimeFormatter.formatDateTechnical(localDate);
+    let timeStr = TimeFormatter.formatTimeTechnical(localDate, TimeFormatter.settings.showSeconds);
+    return `${dateStr} ${timeStr}`;
+  }
+
 }