I opened a bounty on http://stackoverflow.com/questions/3340810/twitter-social-networking-dataset less than 7 days ago. Though the question has had an answer for a number of days now I was waiting to award the bounty until the last moment. I just got an email and a banner alert indicating it was less than 24 hours to go, so I thought I'd go award it.
When I went to the question I had no such option, what happened to my bounty? (I should still have time left to award it)
To be clear: the banner showed up just before I posted this question, and I visited SO less than 24 hours ago. If the question has already expired, then the banner must've been correct within the last 24 hours (and before), so it didn't show up when it should've yesterday.