If the client doesn't want to make a payment today, they should either mail a check or use IRS Direct Pay. The e-file system doesn't modify dates based on disaster declarations or holidays that don't affect Washington DC.

ok thank you

You won't be able to do a future date after 4/18 but you can do the same date you e-file the return/payment. 

Example: If the taxpayer wants to pay on 5/1/23, if you e-file on 5/1/23 you can put that as the payment date.