Imo, what we do is veg them under 18/6 inside for the first week. Then they go into a green house with supplemental light with the lights turned on for a couple of hrs at night and in the early morning to keep the light at 18/6. Then they get planted in their final homes on june 1st. I am in nor-cal as well. Imo, june 1st is the safe date. I have seen people put clones out ay 15th with no problems and i have seen people put them out may 15th and had them start to flower. I think a lot of it has to do with strains/conditions as well but June 1st is definitely a safe date. Imo if you veg under 24hrs and put them outside it will be a lot of stress. We veg under 18/6 every year and put them in their final homes straight from that with no problems and very minimal transplant shock. They take off right away!