The OpenTable app said that they were open for our 8pm reservation and even to "Hurry, only 4 spots remaining", but the entire restaurant was closed. We didn't make a reservation anywhere else on a Saturday night because we made one there. By the time we showed up to the restaurant and saw it was closed, we could not get a reservation anywhere else nearby.
If a restaurant is going to use OpenTable, they should make sure you cannot reserve space when they aren't even open. The whole night, for a birthday dinner, was ruined.