Refactor: create DateCacheService to reduce date duplication

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

src/app/services/date-cache.service.spec.ts

@@ -0,0 +1,46 @@
+import { TestBed } from '@angular/core/testing';
+import { DateCacheService } from './date-cache.service';
+
+describe('DateCacheService', () => {
+	let service: DateCacheService;
+
+	beforeEach(() => {
+		TestBed.configureTestingModule({});
+		service = TestBed.inject(DateCacheService);
+	});
+
+	it('should be created', () => {
+		expect(service).toBeTruthy();
+	});
+
+	it('should cache today date', () => {
+		const today1 = service.getToday();
+		const today2 = service.getToday();
+		expect(today1).toBe(today2); // Same reference
+	});
+
+	it('should cache today components', () => {
+		const components1 = service.getTodayComponents();
+		const components2 = service.getTodayComponents();
+		expect(components1).toBe(components2); // Same reference
+	});
+
+	it('should cache current month', () => {
+		const month1 = service.getCurrentMonth();
+		const month2 = service.getCurrentMonth();
+		expect(month1).toBe(month2);
+	});
+
+	it('should cache current year', () => {
+		const year1 = service.getCurrentYear();
+		const year2 = service.getCurrentYear();
+		expect(year1).toBe(year2);
+	});
+
+	it('should clear cache', () => {
+		const year1 = service.getCurrentYear();
+		service.clearCache();
+		const year2 = service.getCurrentYear();
+		expect(year1).toBe(year2); // Values should be the same even after clearing
+	});
+});