Swiss tournament

Hello, One question?

When I create a Swiss tournament I try to change the start time but it does not leave me because it says that I have to put a valid value.
How do I change the time of the start of the tournament?
Thank you

I think it depends. For example if you look at this tournament lichess.org/tournament/ZFTrnvQ0 I can't change it because it has already started. You also should check you am's and pm's for it to be valid.

This applies to all tournaments