Here's what it said when I did just that now:
OK, so the deadline was at 11:59:59 and the .zip file was created at 12:03:53. Sometime in those 3 minutes and 54 seconds, a student submitted their assignment. The university has a zero tolerance policy for late submissions, which means that unless this student has extenuating circumstances acting in their favour, they'll get feedback on their work but no marks.
I wonder if it would make any difference to late submissions were assignments to have a deadline of 12:04:59? Or would students still submit four minutes late?
As for the other two students who didn't submit their assignment at all...