Flowering

if the plants are mature and ready for the switch you will see pistils or balls with in a week and a half. If your plants are not mature, they will show later once they get there. this is why 12/12 from seed only flower in week 6 or 8. Good Luck!

Just to be clear - if you veg a plant long enough, it will show you those pistils/stigmas before ever switching to 12-12 This usually happens anywhere from week 6-10 of veg in my experience

From 2 to 10 days depending on strain, maturity and state of plant, sometimes some phenotype of same strain acts different. All the Best ! P.s. my small trick is to prolong night period for that night up to 24 hours when I change light regime to flowering with photo dependent plants.

Depends how long you vegged, and therefore how mature it is.. but usually within 7-14 days as long as you’ve vegged 5+ weeks