API-Filter for dates

Hi,
I’m tryin to do api-request with “filterByFormula”.
I want to filter by date and to filter by range.

I tried something like that, but it doenst work (Gettin no records):
AND((DATUM) >= “02-01-2020”, (DATUM) <= “02-31-2020”)

How do i have to implement this kind of filter?

Thanks for your help!