A couple of minutes ago, I received a system-generated message from the inbox, which says that
Your question bounty is completed and will be auto-closed after a 24-hour grace period.
But then I refreshed the question page immediately and saw the following message:
This question has an open bounty worth +250 reputation ... ending in 37 minutes.
While this is not really an important issue, I am curious to know if there is any knwon reason for this time lag of 37 minutes long. Also, which time is the true endpoint of the bounty period? The one indicated by the inbox or the one on the question page?