12/12?

Is it important to have the light on exactly 12 and 12?

yes at all times

i wouldnt say exactly, but i just saw a post EXACTLY like this

Once the plant starts to produce the hormones that trigger flowering its not good to have the light cycles different each day. Although the most important aspect is the plant receiving 12 hours of darkness.
This is could lead to some debate on hours on verses off with a few growers, its common place to run 12/12 light cycles.
A 10 dollar timer will keep it consistent.....

i would say that its important to have a constantly repetative photoperiod during flowering. If you miss your lights off time by a half hour or an hour continuously, and you confuse the plant on when its supposed to go to sleep, its gonna stress out and possibly turn hermie. Same for lights on. It should be the same time off n the same time on every night.

If you end up turnin your lights off a half hour later one night by accident, make that your new lights off n lights on time for a couple days, and then gradually ween it back by about ten minutes a day, until your back to your preferred on/off time. Get yourself a timer bro, makes your world a WHOOOOOOOOOOLE lot easier, lol.

good luck man!!

-K1.