Does length of eating period matter really? For example, I completed an 18 hour fast at 1pm today and I want to start my next 18 hour fast at 6pm.
No, of course not. I mean fasting is a lifestyle that generally benefits most of the people. And it is flexible since it is a part of life. I am doing 20-4 but in two hours I can take my daily calories so I am starting my fast, so it resembles more like 22-2 which is not common. Sometimes I go 16-8, sometimes I eat whole day 🙈 As long as you have the control about your respected goal, it is fine.