After the official 4/18 due date you can only schedule a payment for the day of filing, so you can only make a payment for todays date 7/14/2023.  If youre entering todays date and still getting an error, you may need to update your program.

If you want to make a payment for a date in the future, go over to IRS Direct Pay and you can choose a different date for the payment to be debited.