? about cancelling a NFS site through Recreation.gov

We have had a reservation at a very popular national forest campground in Colorado since January.

We have (almost) changed our minds and want to go to another campground instead (this one doesn't accept reservations).

So I would like to post the site opening up on this forum just prior to cancelling the reservation. If I cancel, for example, on a Wednesday, does anyone know when the site will show up as available? Would it be immediate or on Thursday morning?

Thanks!