I'm not sure if I have correctly understood your problem. You have created a Calendar table and I think you have another one with user's issues.
If you want to filter user's issue data using the calendar data, it is neccesary to make a relation between both tables. For doing this, use the same name for issue's date field (in user issues table) and the correspondant one in Calendar
Just to make sure (because the calender can be tricky) when you look at you table view (CTRL+t) do you see both tables connected on the Date field?
If so make a Table box and select [Date] and [Datum Aanmelding]
These 2 rows should match. If they dont, you have to take a closer look at the date format your data source.
If they do match please share an example of your Excel sheet then we can have a closer look.