Device Time Change to get around curfews - Win7 x64

My son is able to change the device time on his Windows computer to subvert the curfews monitored by Norton Family.

Norton Family detects the device time change (good), but does not report it to me immediately (not so good), and does not prevent it (not so good either).

Is there a way to prevent user time-changes on the monitored machine?  Alternatively, can I be immediately notified?

By way of explanation. curfew cuts in at 8pm.  At 7:40pm with impending curfew, the time was changed to 5:40pm to allow continued use!  I discovered this 2 days later, by luck, when checking alert logs.