OZG-2419 Unit Test fixen

goofy-client/libs/tech-shared/src/lib/date.util.spec.ts

 import { registerLocaleData } from '@angular/common';
 import localeDe from '@angular/common/locales/de';
+import { format } from 'date-fns';
+import { de } from 'date-fns/locale';
 import { formatForDatabase, formatFullDate, formatFullDateWithTimeAndDay, formatFullDateWithTimeWithoutSeconds, formatToPrettyDate, formatWithoutYear } from './date.util';
 
 registerLocaleData(localeDe);
@@ -43,8 +45,8 @@ describe('Date Util', () => {
 	describe('formatToPrettyDate()', () => {
 		it('should format date without year', () => {
 			const today: Date = new Date();
-			const day: number = today.getDate();
-			const month: string = today.toLocaleString('de', { month: 'short' });
+			const day: string = format(today, 'dd');
+			const month: string = format(today, 'MMMM',  {locale: de});
 
 			const result: string = formatToPrettyDate(today);