If you submitted your state tax returns by 1pm CST on the 15th, but they were accepted on the 16th, you generally won't be subject to a late filing penalty, especially since you don't owe money to either state
States typically consider the submission time rather than the acceptance time for determining lateness
For more details, you can refer to TurboTax's state tax tips
Reach back your state - to check on state-specific rules.