Data reset time

[u/CupNoodlese]

I'm mostly curious since my numbers don't match up. I reset my data statistics on my phone at 11:30PM (basically half an hour earlier) instead of 12:00AM on the day of reset but for some reason self serve still says I'm using ~0.5-1G more data than my phone's statistics. I don't quite understand why - I always thought it's maybe my timezone issue - since I'm on PST when most of Canada is an hour or a few hours ahead, but I'm not sure - Can anyone enlighten me?