When to add cherries to a stout?

I know they go in the secondary, but I was wondering if I brewed a Dry Stout with a OG of 1.045 how long does it need in the primary before I can put her in the secondary with some tart cherries?

I am hoping this is ready by St. Paddy's but I only brewed it a week ago.

recipe is always helpful. My dry stout is usually in primary 3 weeks than into keg..A dry stout is a nice quick beer for drinking..however adding cherries or other factors can make it age a bit slower until peak..however I would say 2 to 3 weeks in primary than an other 2 weeks on the cherries would be good..It should be fine for st. pattys. IMO however I would not mess with a good dry stout..cherries are nice but its a dry stout..good by itself

Sweet, that was about my predicted schedule. Just needed a confirmation on time frames.

Recipe in case you were interested:
2 row - 7lb
Flaked Barley - 1.5 lb
Black Barley - 9 oz
Roasted Barley - 8oz

Perle (7.5%AA) - 1oz FWH

This turned out so freaking good! Nice hints of coffee and a really mild cherry taste in the background. Not overwhelming at all. Good choice for a first fruit beer.