Maybe you live in Hawaii like I do.  When I opened Proseries  11/21/20, there was a follow-up message saying although the IRS processes until midnight, they would shut down at 9pm EST to allow processing time for submitted returns.  That meant I had to get my return in by 3pm if there was a 6-hour difference.  It might have been a 5-hour difference because I was able to correct a rejection and resubmit it.