[SOLVED] Query date 1 >= date 2 doesn't work

Can you be so kindly to explain, how I can implement your suggestion with a code field? What I have to do?

Additionally you can probably just use Code validation using CB Code Field and do this with PHP as I don't see any specific logic that would require SQL in your usage. Example as follows with PHP.

Code:

return ( strtotime( '[cb_tauschdatum_ab]' ) < strtotime( '[value]' ) );

Can you be so kindly to explain, how I can implement your suggestion with a code field? What I have to do?

Add code validation to the field under Integrations > CB Code Field and add the supplied code to it. Adjust the field name as needed if cb_tauschdatum_ab isn't correct. In the supplied example if cb_tauschdatum_ab is less than the value they selected it should fail validation.