How much of a grace period will they give you? I'm not planning on being late, but hey you never know (like what if the monorail breaks down with us on it?)
How's that for an answer. In general Disney is fairly flexible on arrival if there is a legitimate excuse. But you run the risk that the restaurant is booked solid and is already running 30-45 minutes behind. If you're there within 15 minutes, you're more likely to get in.
1) Usually, ADR's are good for 15-minutes.
2) In lax times, you can just wait for another table to open.
3) On busy days or times, you forfeit the ADR, and go to back of list.
I was told after 20 mins your ADR is automatically cancelled.
We had an ADR booked at Tusker House for breakfast one morning and decided to eat at Cape May instead. I asked the CM at the podium to cancel my Tusker House ADR thinking someone else may benefit from it. She told me not to worry about it, that it would cancel itself 20 mins after my scheduled ADR.
We have been late a couple of times and early. Neither has ever been an issue. Just keep in mind that your ADR doesn't mean you get a seat when you walk up. Expect to wait 5-15 minutes from the time you check in. When running late or early it might be a little longer.
As others have said though there are no promises. If you are late you could get turned away - particulary at a really, really busy time.
We always book for "off times" - 3pm or 8pm instead of 5 or 6pm for example. I think that helps...
We've only been late once, maybe twice due to unforeseen circumstances and never had a problem. However, it all depends on the hostess really, I guess.