I went to see Days of Future Past by myself yesterday afternoon, at the 1:15 PM 2D Digital showing. Or, rather, 1:45, due to 30 minutes of previews, and random commercials.
Due to a particularly urgent need, (four glasses of tea before going since it was 90 degrees, you figure it out) I left the minute the end credits began. I already knew the gist of what happened in the end credits scene, and I located a low quality version of it a couple hours ago on Youtube.
Without spoiling (spoilers are welcome in the comments, though) anything, I will say that I loved it.