depends.. can take up to two weeks.. generally you are looking at 3-4 buisness days... however if its a mom and pop and they (unluckily for you) have their account at the same bank you do, it could potentially clear tonight or tommorow (depending on when you wrote the check). Theres no real set length about it.. alot of variables.. generally speaking if you get it in the next day your good.
The only really lucky news is they cant cash the check (so it wont have allready cleared) since its made out to a buisness.. for tax purposes those have to be deposited.