you know the flowering time should start when you see flowers not when you switch them to 12hrs it can take weeks for a seed to first mature
I disagree.
The best way to measure flower time is the number of days between switching to 12-12 and final harvest maturity. That's irrespective of when the plant actually starts forming flower clusters, and if you think about it, its the only real way to compare flowering time between lines. No other way of measuring makes sense.
If a plant takes fully two weeks to start making flowers (and this happens with some lines) that's part of the ticking clock, and you're going to want to factor that in when you consider/buy/grow a strain. If some breeder tells me their line takes two weeks to start making flowers and then seven more to finish, that's not a "seven week" line, its a nine week one.
As a few general rules I've found with respect to flowering times:
-Older plants (ie clones from moms) will typically start making flowers faster than young plants from ceed just out of veg. The difference here can easily be 7 days faster from clone.
-Irrespective of what the breeder claims, in my experience most hybrid strains take a full 9-10 weeks to finish. Sativa heavy ones typically take longer.
-For marketing reasons and again because of industry pressure, breeders tend to understate the real flowering times. EG, a "7-9" week line probably isn't going to be really done until week 9 or maybe even week 10+.
-Flowering at 11 hours light 13 dark (instead of 12-12) can be helpful to speed things up a bit, especially with sativa-heavy lines. This will typically save at least a week, though you'll give up a bit of yield too.
As to ceed maturity, that's a little bit of a different question, but I'd say it takes at least 4-5 weeks after pollenization to get viable ceeds from fertilization from pollen, and longer is better.
