Outdoor Flowering Help

ok so its my first grow outdoors and what im wondering is does anyone know when outside plants in Maine or the Northeastern United States start to flower ? if i go by the natural 12/12 lighting cycle that doesnt start with 12 hours of darkness until sept 20 sumthin so is that when my plants will start to flower ?

If not already they should start any day now.big factor---- strain?

Well the ones I'm referring to are just bag seed but I got sum autoflowers going as well but I ain't concerned bout them obv lol the

Well maybe this would help ur in the northeast right ? And urs are outside and there flowering ? If so mine probably are to maybe I'm just being paranoid but I was gonna put them into force flower just in case I just really need these done by october