The wheels reset at the same time everything (daily scores, bug of the day) does its daily reset. It's around 6 am CST (give or take).

There was a bug yesterday that allowed some of the wheels to be spun more than once. I think the lag played a part (it only seemed to affect the "busier" wheels, in the fan and the zone). Everything seems to be working correctly now.

I can't say I was complaining.