I went to University that had a similar deadline system (sometimes midnight, sometimes midday, sometimes 3pm - all depended on the lecturer/tutor). If you had

I went to University that had a similar deadline system (sometimes midnight, sometimes midday, sometimes 3pm - all depended on the lecturer/tutor). If you had a truly extenuating circumstance, you could always speak to the lecturer via email or during their office hours. Some had more relaxed policies than others, while others had various penalties for being late. As far as I'm aware, the difference between 12:00:00 and 12:00:30 wasn't ever really a thing, as any reasonable system can expect a few minutes of delay owing to computer problems.