Are there multiple Arena payouts per day? Maybe different time zones pay differently?

There are 24 timezones, so 24 different payout times. There is a payout every hour. The guy moving up behind you is most likely in the timezone west of yours. It is good etiquette to wait until an hour or two before your payout to make any moves, and not mess with people not in your timezone. Everyone hates that guy that thinks he has to own the number one spot at all times.