Most strains begin budding about August 1st, give or take a week.
On the equinoxes, the entire plant has a day of 12/12.
The Summer and Winter solstices vary from zero to 24 hour days, depending on which pole you're standing on.
Where I live, my longest day is a bit short of 15 hours and shortest a bit more than 9 hours.
12/12 isn't required to initiate budding.
Just an extended period of day length reductions. Usually five or six weeks, outdoors.