Sarah, you asked me some questions above.
1. My 'window is about 3 hours.
2. I have now been doing this since mid August. Otherwise I do it regularly twice a year. This Autumn one is extra.
3. I do it every single day, because the body gets used to this way of eating in about two weeks, and I do not want to upset that.
4. At around 15:00 I have 'afternoon tea', My window opens and I have tea with milk, yogurt with berries and apple and a bit of sugar-free Muesli.
Then eat nothing until dinner time. Which I have whatever we're having that night. But low carb. My husband has potatoes or rice/ I have salad or cooked low carb veg. I close my window soon after 6 pm. And do not eat anything until the next day at 15:00.
This week end, however I am going away and I cannot keep up the window eating then. Saturday and Sunday will be different!!
Hope this answered your questions