Rebigulator is right. Even as a plat I almost never get EUA'd EWR-SFO-EWR.
All the folks saying early morning are wrong, however. The redeye is your best bet for getting EUAed. Especially the saturday night redeye. That's as good as you're going to get on this route. Of course, I'd rather fly in coach than take the redeye (especially on saturday night!), but there you go.
There is no redeye from EWR to SFO (which is the flight in question). Only the other way around.