This is a much debated topic of when to start the flowering count and personally I could care less....BUT, I start my count when the plant starts flowering and my finish times are much closer to the breeders recommendations. Having said that, if you were to use that method, you will find yourself short of 60 days.
Your plants totally look like they are still maturing. I'd give them another 10 days or so and then post some more pics. Hopefully at that time they will be closer to finishing and you can start your flush,