That's only 56 days from my post, 2/26/2015 and it looks like you need 3 weeks to a month IMO. Those buds are nowhere near ripe looking at it zoomed in.
If you cut too early all that time effort goes down the drain as the high and potency is not good. Even if they say 60 days, 70 days or even more is more realistic.
From a top bud of your plant I screen shot so others could see better.
Not ripe, I'd wait a while.
Here's a pic of a ripe bud.
And one of my last ones with similar lighting as yours that was said to be 50 something to 60 something days but I needed to wait 73 or so days and really it could have gone longer.