I have been doing what the author describes for some time now (although I dont get up as early) and I find, that it works well to go to bed at any time on frida

I have been doing what the author describes for some time now (although I dont get up as early) and I find, that it works well to go to bed at any time on friday & saturday evenings as long as you give yourself enough time to sleep in as long as you want on the following day. On Sunday however, I will go to bed just as "early" as on e.g. Monday.