/// <summary>
 /// uses calendarRepository for getting the newest list from server
 /// </summary>
 public async void ShowAll()
 {
     CalendarEntries.Clear();
     _fullEntrieList = (await _calendarRepository.GetCalendarEntriesAsync()).ToList();
     CalendarEntries.AddRange(_fullEntrieList);
     NotifyOfPropertyChange(() => CalendarEntries);
 }