Did you use lights to extend the length of day? With seedlings you have a little grace period of 4-5 weeks until they are sexually mature, but clones are already there.
Sure didn't actually, for me it wasn't really necessary because I was living in Southern California at the time. I just looked up a daylight schedule and that helped to determine when the best time for me to plant was. After the winter solstice, the amount of daylight we get starts to gradually increase until the summer solstice when the amount of daylight we get starts to gradually decrease as the days go by.
I'd pop my seeds in mid April when the amount of daylight was 14 hours, however you may even be able to get away with starting them in March. Even though there's only 13 hours of light in March, the amount of daylight increases. Flowering won't be triggered until the daylight starts to decrease day by day. It all depends on where you live though, you'll need to look at the amount of daylight you get and when.
For Southern California, starting seedlings outdoors in March-April is optimal because they'll continue to veg until a little past the summer solstice. Eventually the plants will begin to flower at their own pace when the amount of daylight starts getting shorter and shorter. It's been years since I've grown outdoors so I forget the exact month the girls would start throwing out pistles, I think it was around July for me. Harvest usually came around September or October, depended on the strain.
Just keep in mind that your light cycle doesn't have to be exactly 12/12 to trigger flower. Flowering is triggered by your light cycle getting shorter, not so much the amount of light you have. That's why going from 18/6 or 24/0 down to 12/12 will trigger flower. It's not the 12 hours of light/dark that triggers flower but the fact that the light cycles are getting shorter.
HTH.