Different start times

That would make sense if Mabi's servers modeled Erinn time off of a mapping between real-world time and time of day/date in-game, but I don't think that's the case... it seems more likely that the clock position is calculated when the server's initialized and then incremented at a constant rate, which both explains why desynchronization occurs and why the amount of it varies across servers (whose individual loads fluctuate during the day)

Just my $.02

Edit: okay, yeah, now they're noticeably spaced apart. Lost early on on ch T-06 and had enough time to get to the T-02 quiz field before it started there. I guess the servers' timefail will continue to be a mystery.