No, because it doesn't matter.
There isn't a set light schedule that 'snaps' plants into flowering. They begin to flower after they sense the days becoming shorter.
12/12 is only used indoors. The sharp contrast between eighteen and twelve hours of light immediately induces flowering. Outdoors, the change is very gradual.
Your plants will start flowering, probably, sometime in early august. Which would be like 13¾/10¼.
If you took 30 seconds to do a search you would see that five people a day ask when 12/12 starts in their area, and are all told that it doesn't matter. I just wanted to give you another chance to find the info for yourself.