The scenario I see here is that the post was created at 1:27 UTC on December 24, it was originally scheduled as immediate, but when the author realized the mistake he/she changed it to be December 31st. However, the publishing itself is a separate task, so it was going out as the change was being made. If an edit was initiated while the post was still pending, but then we published, and then they saved the changes, the last change with the schedule date would have been accepted.
