The check is payable on demand during business hours. Otherwise the check's no damn good. That the fed banking rules.
Lets say client A has 100,000 in his checking account and he writes you a check for $500.
If you come into the bank and ask to cash it, the bank is under no obligation to cash it for you.
Yup. And the UCC codified in all states covers negotiable instruments. Banks have a fiduciary obligation.
You could write a check on a coconut and they would have to honor it.
It is the INTENT of the payer.