Your comments

For anyone who happens to encounter this, the problem was that the system defaults to midnight in the absence of a time. So I was in essence saying an event starts today, ends tomorrow, and then repeats tomorrow and ends the next day. It wasn't able to do that. By just putting in an end time before midnight, I could have resolved the problem.
It's in the admin side. I have a saved search of editorial assets for the day, which is sorted in descending order. As I upload new stories and refresh the view, the new stories frequently do not appear at the top as they should. I'm attaching a screen of shot of this view. The one with the arrow is just one of the ones out of order. They are sorted by date, but not by time, it appears.