I believe that it's when the clock ticks over from the 21st to the 22nd that submissions come to an end.
I'll verify, and if that is not the case I'll reply back.
Good.
Just in case, here is a screenshot. As I understand it, my local time is displayed at the bottom, and the time in the Pacific Time Zone is displayed in the pop-up frame.
But this is slightly at odds with the time indicated at the top :)
Thanks for this!
I'm not catching the problem. I'm looking at it now. End of day on July 21st is 7am July 22nd UTC (Pacific is UTC -7). That is when it is ending.