In 99% of cases, you won't need it but InviteMember allows changing one-time payment dates directly with a special /edit_payment_dates command that you can send to your membership bot:

/edit_payment_dates PAYMENT_ID EFFECTIVE_FROM EFFECTIVE_UNTIL

where

PAYMENT_ID — payment ID, you can get it from @InviteMemberBot under Export data > payments.csv (see internalID column)

EFFECTIVE_FROM — when the access should start

EFFECTIVE_UNTIL — when the access should finish

For effective from & until dates, you can use the following formats:

2021-09-02 (simple date)

2021-09-02T09:30:21+00:00 (date, time and a timezone, +00:00 means UTC+00:00)