The one I've heard most about is 16:8, which would mean e.g. first meal being lunch at 12 and last one dinner before 20, resulting in a 8-hour eating window, an

The one I've heard most about is 16:8, which would mean e.g. first meal being lunch at 12 and last one dinner before 20, resulting in a 8-hour eating window, and a 16 hour fasting one.