Hi there,
Welcome back to the Community. I'll be happy to share more info on how to change the date on the tax payment cheque.
To do this, click on Expenses from your left navigation menu > locate the cheque in question > click View/Edit > change the date. After you've done this, make sure to click Save and close. Try this on your end and let me know how you make out. I've provided a screenshot below for reference.
If you have other questions, don't hesitate to reach out. I'm here to assist. :)