It was a bit of work. Open the Smart Actions app, pull up the menu, select My Profile, and then select Timeframes. Now create a timeframe for every period of time where you don't want the phone to do synchronization. I'm using these: 1am-5:55am, 6am-6:55am, 7am-7:55am, etc., hourly until my last one at 12am-12:55am. Then create a timeframe trigger that employs all of these newly created timeframes, having the smart action disable cellular data for each of these timeframes.
I would have preferred a little bit more support for doing this sort of thing, but this works.