Yes - I really do, because I created them in tested. I don’t want the app to accept these entries.
I expect that when you select a Start Datetime after the End Datetime, then the “Submit” button would be disabled. Instead, the button is enabled and clicking it adds the event.
If its form, the data is accepted regardless and the computations happen post data entry!
I would suggest deleting the entry if not acceptable by your conditions added and showing a notification like “Error saving entry log”
As @ShantanuIyengar said, there’s no real validation in a form environment to disable the submit button as you want.
If you need it to be validated at that stage, create a custom form. Disable the submit button with your condition should work, because it’s a visibility condition at that point.