If you want peak THC potency, harvest when there are about 95% brown pistils, be that today or in 2/3/4 weeks time.
The times given are only a guide, not hard and fast rules.
Dropping your light cycle by one hour can get her to finish flowering faster, if you are pushed for time or she proves stubborn to finalize and keeps on growing more and more new calyxes, which can occur with Sativa dominant plants, particularly like anything with "Haze" in it.
Hope this helps, Organoman.