will dry-hopping longer than a week matter?

I'm thinking of brewing next weekend, but looking at my calendar, I'm not sure if I'll be able to do the primary->secondary, and secondary->bottling when the recipe calls for.

In particular, I'm wondering if dry-hopping past the recommended 5-7 days will affect the beer. Will the hops just lose any affect after a certain amount of time? Or will they actually start contributing off-flavors? Thanks.

I think the recipe calls for 2 week primary, then 5-7 days of dry hop in secondary. I might end up with 3 week primary, 2 week secondary.

Thanks.

leaving them in too long can cause a grassy flavor, usually undesirable.

people dry hop in the keg for long periods of time.

Yeah, I've dryhopped in cornies with no off-flavors. These days I tend to dry hop after fermentation is done, for about 10-14 days.