CommentStreams:Afdd6cd04a465de0df2cb2d48f89e546

most likely for each account the guilds that you  have been a part of in the the last 24 hours are recorded in a list on your userdata or similar..

And the list is updated each time you leave a guild. That is how i would do it.

SO if they did it the way i said then you cannot rejoin any guild that you 've already been a part of in the last 24h.

Maybe someone can test that.