Growing Nanking Cherry From Seed

I got some Nanking Cherry seeds and understand they need stratification to germinate properly. Everything I read talks about keeping them in a moist medium in the refrigerator, but the amount of time is very different - everything from 2 to 12 weeks. I want to plant them this year so what kind of time in the fridge are we really talking about? Can I get away with 4-6 weeks?