[Typo3-dev] a question about TCA

[Mario Rimann]

Hi all!

I'm working on an extension and there I got this "problem" about
TCA:

There is one table with some fields. One field holds a datetime
(when does this event start). Another field should hold another
datetime (until when can somebody register (deadline)).

Is there a way, to evaluate this second field via TCA. It's value
must not be larger (= later) than the first field.

Has somebody a clue about how to solve this?

Greetings from Switzerland,
Mario