If your return has already been filed and accepted by the IRS, you can't change the payment date in TurboTax. You'll need to contact the IRS e-file Payment Services at 1-888-353-4537 to see about changing it.
If you need to change the payment date for your state tax return, contact your state tax agency.
Note: If you haven't e-filed your return yet (or your return is in Rejected status), you can revisit the File section in TurboTax to either correct your account information or choose a different tax payment method.