Depends on the cigar. I like to get to each box every 6 months or so to check on the progress. If they taste fantastic, I'll smoke a bunch. Some will age a month, some 6 months, some a year, some 5 years.
Varies too much to put a definitive answer on. The size of the vitola and blend of the marca has alot to do with it. Obviously, you're going to need less time with a Partagas Short than you would need with a Sir Winston.