The order of posts here on itch confused me a bit, as it depends on whether you reply to someone or not. Thus I will here try to make my question more clear:
I don't know if the displayed deadlines adjust to the time zone of the viewer but here in Denmark the text is this:
"Submissions open from March 21st 2022 at 10:00 AM to May 1st 2022 at 12:59 AM"
Thus, if I take rule 13 literally, I can only make my game public within one hour (1st of May 12:01 AM to 12:59 AM). Or it could mean, that as long as it is the 1st of May somewhere in the world, i.e. 12 hours before it becomes the 1st of May in the UK. Or it could be, that the text in the UK is:
"Submissions open from March 21st 2022 at 9:00 AM to April 30th 2022 at 11:59 PM" and that we can reveal our game all day on the 30th of April.
It would just be good to know so we don't get disqualified for that .