Those pistils are still thick and white, and the calyxes don't look all fat and bloated yet, so they will definitely get bigger and gain weight. I'd say 3 to 4 weeks at least, but I've never grown that strain.
Check out some grow logs and note how the flowers start off as a bunch of white pistils, then as the bud develops, those white pistils start to go from looking like little white strings, to thin whispy white hair lookin' things, and then to receded brown / red "hairs". As soon as you see most of the pistils start turning brown / red, you'll know they're getting close to being done.
Regardless, your plants look very nice, and I'll bet they deliver some great smoke. Luck to you and your harvest.