You can set your eating window at whatever time of day works for you. IF should fit your lifestyle, not the other way around. If you’re a night owl and you prefer to set your eating window between 4 PM and midnight, go right ahead!
There are some studies I’ve been told about that discuss eating at certain times are better than others for better digestion and metabolism but I think ultimately everyone is different. Experiment with what you prefer and see what works best. My preferred eating window is 7-11 pm (20:4) and I’ve seen great results.