Can my intermittent fasting window be flexible?

You can rotate it. You can change it up. I think you should change it up to see what works better for you. For example, in the past, I would eat at my first meal at 2 or 3, and then the second meal at 6 or 7, right? And then recently I tried to eat earlier, and then the second meal maybe at 2 o'clock, maybe 3 at the very latest. So you want to experiment with that.