Ok, while writing my last message you added that you believe they are California Kush. I have never heard of that particular strain so I cannot be of much help but in general Kush genetics, according to everything I have read, are indica or indica dominant plants so unless your cross has a high percentage of sativa in it, and if so I would be surprised it would still be called a Kush, I would have to say they should be finished or very close to being finished so just look at the trichomes daily and then take them when they are the color that will give you more of the type of high/buzz you like.
Of course you cannot turn an indica buzz into a sativa high just by harvesting when the trichomes are milky and you cannot take a sativa high and turn it into an indica buzz just by harvesting it when the trichomes are amber but you can of course somewhat fine tune what you get by making such choices. The majority of what you get will be based in the strain/hybrid’s genetics.