This question already has an answer here:
I just want to know if SO has some sort of cutoff time per day? Is it fixed in one time (e.g. 00:00) or has some sort of related to when you have registered? (Scenario: For example I registered at exactly 2pm then the next day 2pm would be the cutoff and count as one day when I login). If not, what time is it? Is it applied to all SE Network?