AS soon as a account holder signs a check it is supposed to be good , changing the date may not even be caught by a bank , since checks are electronically processed. Not likely there is much to do but live with the bounce fee (s) and don't pot date checks any more. BTW many years ago when banks did have a job called proof reader to process checks I had forgotten to sign one check ( I think it was a utility bill ) so any way the bank paid it anyway with out my signature )