Further optimize: simplify heuristics calculation and cache component values

Co-authored-by: THoguet <61246905+THoguet@users.noreply.github.com>

src/app/components/calendar-year/calendar-year.ts

@@ -16,6 +16,10 @@ import { CalendarSettingsService } from '../../services/calendar-settings-servic
 export class CalendarYear {
 	protected isLoading = signal(true);
 
+	// Cache current month and year to avoid repeated Date object creation
+	private readonly currentMonth = new Date().getMonth();
+	private readonly currentYear = new Date().getFullYear();
+
 	constructor(
 		private userInput: UserInputService,
 		private calendarService: CalendarService,
@@ -45,13 +49,10 @@ export class CalendarYear {
 	protected selectedDates: SelectedDates = new SelectedDates();
 
 	getYear(monthIndex: number): number {
-		const offset = new Date().getMonth() <= monthIndex ? 0 : 1;
+		const offset = this.currentMonth <= monthIndex ? 0 : 1;
-		return new Date().getFullYear() + offset;
+		return this.currentYear + offset;
 	}
 
-	// months starting from actual date
+	// months starting from actual date - cache this array
-	protected months: number[] = Array.from(
+	protected months: number[] = Array.from({ length: 12 }, (_, i) => (this.currentMonth + i) % 12);
-		{ length: 12 },
-		(_, i) => (new Date().getMonth() + i) % 12,
-	);
 }

src/app/services/calendar-service.ts

@@ -469,27 +469,16 @@ export class SelectedDates implements SelectedDateInterface {
 				return aStart - bStart;
 			});
 
+		const oneDayInMs = 24 * 60 * 60 * 1000;
+
 		// PRIMARY: Optimize adjacency - reduce "little holes" between vacation periods
 		for (let i = 0; i < sorted.length - 1; i++) {
 			const current = sorted[i];
 			const next = sorted[i + 1];
 
-			// Get dates as UTC strings to remove timezone issues
+			// Use timestamps directly - dates should already be normalized
-			const currentEndDate = new Date(current.range.end ?? new Date());
+			const currentEndTime = current.range.end?.getTime() ?? 0;
-			const nextStartDate = new Date(next.range.start ?? new Date());
+			const nextStartTime = next.range.start?.getTime() ?? 0;
-
-			// Convert to date-only strings (YYYY-MM-DD) to compare calendar days
-			const currentEndString = currentEndDate.toISOString().split('T')[0];
-			const nextStartString = nextStartDate.toISOString().split('T')[0];
-
-			// Parse back to dates at UTC midnight
-			const currentEndDateNormalized = new Date(currentEndString + 'T00:00:00Z');
-			const nextStartDateNormalized = new Date(nextStartString + 'T00:00:00Z');
-
-			const currentEndTime = currentEndDateNormalized.getTime();
-			const nextStartTime = nextStartDateNormalized.getTime();
-
-			const oneDayInMs = 24 * 60 * 60 * 1000;
 
 			// Check if adjacent (next day) - this is the best case!
 			if (nextStartTime - currentEndTime === oneDayInMs) {