2-3 weeks, you want the pistils to be red/brown and shriveled back into the caylx. The trichs should be cloudy. The amount of amber trichs you want is a personal preference.
If your Kush autos popped on May 5, theyโre about 9 weeks in now. Most autoflowers take around 10โ12 weeks from seed to harvest, so youโre getting close! Check the trichomes, cloudy with some amber means theyโre ready. Youโve likely got 1โ3 weeks left.