Generally I'm a 4-6 week in primary but I've gone for 3 months and the beer turned out great. We've had some folks leave it in primary for longer than that and it turned out fine. It takes many, many months before you get off flavors. In fact, leaving it for several weeks on the yeast cake removes many off flavors.
Batch 1 Brewing
The American Revolution would never have happened with gun control.