It depends on the time of the day... These are trades on the NQ today between 6:00am and 8:00am NY: After RTH Open the times are generally sub minute for winners and 1.5 minutes for losers.
Which trades? The bracket trades in a fast-moving market? "Faster than I can exit by hand." The primary trades in a 3-10day program? ~7 days. The secondary trades meant to nip the turns of the primary program? ~1-2 days, but of a 2xfund.
From seconds in high volatility up to a couple of hours in very low volatility but I am a singles hitter lacking the temperament to sit through a lot of back fill and retrace.
I hold as long as possible. If I feel very good about a stock, then I will risk a little bit of profit to see how much higher it will go. Some of my day trades end up being swing trades.
4 trades so far this week with an avg of 12hrs per trade. lately, been opening trades at futures open and profit target hits mid-morning (hard to lose going long lately).