I'd suggest that you keep them on a schedule as close as possible to what you do at home. Do you nap from 2-4 and then eat at 5? Then do that. Do you have juice when they get up from naps and delay dinner till 6:30?
Where are you coming from? If you are from CA, they'll be adjusting to the time change...and you'll want to eat earlier.
As above, the early ADRs will have less wait than something like 6p. You can probably shift the kids 30 minutes without much problem, but if you try to change their schedules by hours, you'll be having whine with your meal.