There's nothing more frustrating than showing up to vote on Election Day and finding that the polls have already closed. And since the polls close at different times in different states, it can be hard to keep track.
In Hawaii and parts of Indiana and Kentucky, for instance, they close at 6 pm local time, while New York keeps them open until 9 pm. This map (using times gathered by Jeff Singer at the Daily Kos) shows the poll closing times for each state. Everything is in local time, for maximum convenience:
CORRECTION: An earlier version of this map implied that all of Nebraska sees polls close at 8pm local; while that's true for most of the state, portions on mountain time see them close at 7pm. It also stated that polls in Alaska closed at 7pm, when they close at 8pm (we miscalculated due to Daylight Savings). We regret the errors. We've also changed Washington, Colorado, and Oregon to grey, as they're vote by mail states and so poll closing times aren't really applicable.