As many already know, studying for the physics GRE and getting accepted into a graduate program is not the final hurdle in your physics career.
There are many issues current physics graduate students face such as studying for their qualifier, deciding upon a field of research, choosing an advisor, being an effective teaching assistant, trying to have a social life, navigating department politics, dealing with stress, utilizing financial aid, etc.
They might accept it... not sure how they do their thing. Since the panel doesn't start reviewing these abstracts until weeks from now they may have an accepting deadline extending beyond 5 pm. I doubt they start sorting the material at 5 pm on a Friday. Then again it may all be an online sorting method. Did you get a confirmation email? It's a generic email that reads as follows:
This email provides you a copy of the abstract that was submitted for your records. This is not a confirmation that your abstract has been accepted. Abstracts that meet our guidelines will be placed in the program at a sorters meeting. You will receive notification with details of the placement of your abstract in the program at a later date."