impossible to tell by those pics, but if I were to guess probably another 2-3 weeks....your pistils still look very white and fresh.
the tips will start to turn brown soon.

you also need to infest in a 30x or higher magnifier so you can look at the trich's that's the only surefire way to determine harvest time.

you're plants are looking SO sweet, don't wait on getting a magnifier!

one question...where did you buy that HPS lamp? it looks kind of small, I'm needing a small one but I can't find anything small