Once you report a post, it is sent to the moderator and it stays as unhandled until it has been handled, at which point it will then be marked as good or bad depending on the mod's decision regarding the post you reported.

There is a certain number of posts you should have reported before you will be able to see which of your posts is marked bad and which one is marked good, but for duration there is no max duration to how long it will take; it all depends on the moderator in charge of the board and how busy he or she is or how complex the post you reported is to determine its action.