Hey Mad,It doesn't matter when you calculate flower started, it's the finish that matters. Get your magnifier so you can see whats what. Myself,when I take a look and see a half dozen amber trichs out of 50 or 60 I start my flush. I've found that regardless of what the seed co. says each one of the little darlins march to the beat of a different bongo. They'll let you know when they're ready.