Power out for 1-8 hours...quick question

Well when my friend woke up and checked on them his light was out... He was asleep for 8 hours so I really don't know exactly how long the light was off. Anyways he has them on a 24 hours light and are starting week 4 from seed. My question is this going to "confuse" his plants with negitive results? Also I'd like to know if their any kind of fault tolerance he can implement for future powersurges? The setup a digital 1000 watt lumatek with 450 cfm fan/filter combo in 5x5x7 tent both fan and filter are not on a timer yet but my friend has already ordered hydrofam TM01715D digital duel outlet 7 day timmer rated at 15A/1725 watts. Is their any ways I can get the lights to fire back up without hot-starting the lights? ...also he noticed that the fan was still on after te powersurge and only the light was off. He would also like to know the most cost effective route for dealing with short term power outages (up to 24 hours)

One time isn't going to hurt your plants. Keep it up and you'll have issues.

what about future power surges/outs? is their a way to have te light come back on after power surges or power outs without hot starting it....like something that will wait 15 min for it to cool, the turn light back on