Hi @Biisorte ,
Do you mean that your calendar could only display events based on start date, but not other days?
Is the calendar that you use calendar template screen?
If so, the reason why you met this problem is this formula:
CalendarEventsGallery1's Items:
SortByColumns(Filter(MyCalendarEvents, Text(Start, DateTimeFormat.ShortDate) = Text(_dateSelected, DateTimeFormat.ShortDate)), "Start")
This only filter start field based on selected date (start is equal to selecteddate).
You just need to make a little change.
Try this formula:
SortByColumns(Filter(MyCalendarEvents, _dateSelected>=Start,_dateSelected<=End), "Start")
Then you will filter events based on selected date(start<=selecteddate<=end).

Best regards,