When does flowering start outdoors?

Hey mate, Flowering triggers at around 11-12 hours of darkness. And need then some days to flip into flowering, like 2-4days . The first 2weeks of flowering you wont see pistils and your plant is still growing, but in the pace of lightning literally, so its no easy to keep track on when flowering starts exactly. I would anyways feed grow-nutrients, till your plant shows pistils, since its only growing in early-flowering and therefor needs those nutrients. I would just start flowering weeks in diary, when you hit 12 hours of nighttime or wait till you see pistils and change the last 2 weeks to flowering then. You can put weeks as growing first and switch it later. Hope that helps you, Happy Growing mate!👍