How late can one arrive to a dinner reservation before it is lost?
Technically speaking, an ADR isn’t a reservation for a specific time - there’s no table waiting for you - and usually you’ll be seated whenever you arrive, though you may have to wait a while. But if you’re later than 15 mins, you should check to make sure you’re not charged a no show fee. Some people say they don’t charge until the end of the night but others have been charged while they were sitting eating, so you never know.
There are a few select places that will firmly turn you away. Think places like CRT