Your definitive answer is based on federal, not state law. Reg CC at 12 CFR 229.19(a)(5)(ii) indicates your cut-off time for lobby transactions cannot be before 2:00 pm. Thus, on Christmas eve, your Reg CC dislcosure will be wrong, but you would be violating the regulation regardless of what it said.
Anonymous' advice is steeped in the practical; make adjustments so no customer is affected by the violation.
Any customer who makes a deposit prior to 3:00 pm on Tuesday the 24th is entitled to have the 24th treated as the banking day of deposit. You could 1) on Thursday the 26th research every NSF check (inclearing and over the counter) to see if the drawer made a deposit Wednesday afternoon or 2) celebrate the holidays by not only paying every NSF check presented but waiving the fees as well!
Clearly, it would still be a violation of Reg CC and you could be cited for it.
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In this world you must be oh so smart or oh so pleasant. Well, for years I was smart. I recommend pleasant.