You can't change the date if your return has already been accepted, but according
to the IRS website at Pay
Taxes by Electronic Funds Withdrawal,
-
Once your
return is accepted, information pertaining to your payment, such as
account information, payment date, or amount, cannot be changed.
If changes are needed, the only option is to cancel the payment
and choose another payment method.
-
Call
IRS e-file Payment Services 24/7 at 1-888-353-4537 to inquire about
or cancel your payment, but please wait 7 to 10 days after your
return was accepted before calling.
- Cancellation
requests must be received no later than 11:59 p.m. ET two business days
prior to the scheduled payment date.
[Bolding mine.]