About Calendar Index Errors

MIT App Inventor Help
1

Hello, I'm creating a calendar and when I build and run it, I get the error 'select list item: list too large select list item: apply to get item number 1 of a list of length 0: '... How should I solve this problem?

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also posting aia
planner.aia (370.9 KB)

2

Are you sure to set btn_date to an empty list is a good idea?

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Taifun

3

In my opinion, I tried to make a blank list on btn_date so that I can distinguish between the 31st month and the 30th month and get it.. What should I do?

4

Here's a sample button calendar for you to study:

5

And another example: