our ped endo has told us it has to be within 1/2 hour of his scheduled dose which he gets his at 6am 2pm and 10pm and my son is usually sleeping for the 2 and 10 dose and he takes it and stays asleep for it we just stay up til 10 and then go to bed and set an alarm for 6 am and that gives us 8 hrs of sleep yeah somtimes id like more but keeping my son healthy and getting him is meds is more important to me.  i would rather be safe than sorry.