Under consideration stamp date – Any flexibility on stamped date?

I was given a return on 24-Jun-2021 stamp at the Temporary Visa Extension Center (Muang Thong Thani) and told to make an appointment to do so. Is there any flexibility on the date? Does anyone know if I can make an appointment on the Frii-25 (or Mon-28, Tues-29)? When I got the stamp it was the first time I interacted, in person, with Immigration.

I am 99% sure I will not be able to return on that day, for health reasons.

Thanks for reading and helping