Is his bedtime normally 7 or 7:30 PM? If so, then there's no need to wake the little one up tonight. His bedtimes will not always be exactly the same, no matter how hard you try. (There will be days where he wakes up early or is just tired from the activities and will go to sleep a little earlier. Other days he may end up going to bed a little later because you happen to be out.) As long as you keep a regular bedtime (7 - 7:30 PM is the best time) for most of the time, then things should even out.
However, don't let him fall asleep at that time for 3 or more days in a row because he will make then make this his "new" bedtime. Aim for having him get to sleep at the regular time tomorrow, even if you have to add an extra catnap in the day somehow.
