I've used this sleep schedule before. It's extremely liberating, if only a little lonely at the beginning of each week.
It's not hard to switch back and forth as long as you use one of the bedtimes that's normal for both schedules and just wake up with an alarm when you're supposed to on the new one.
The best thing about it was that I was actually tired (on the 20/8 variation) when it was time to go to bed, and I usually woke up a few minutes before my alarm starting on about the third day. These two phenomena never happen with any variation on a 24 hour day that I've tried. I was more productive (got my normal work done; started cycling regularly again; wrote more; and was averaging 2-3 books per week) and happier. I can't think of anything bad to say about it except that the last few hours of each "day" are a bit sluggish. I'm convinced that helped me sleep.
The only reason that I went off it was because my girlfriend has a fairly restrictive (yet changing) schedule. I was looking at not seeing her at all for a week if I continued it.
I should say that if I just go to bed when I'm tired, my body defaults to something pretty close to a 28-hour day regardless of light levels and the other people I've known to try it had negative experiences.
Yes, my experience was very similar. The nice thing about the schedule was that going to bed and waking up were very easy and natural, so it was easy to switch to the schedule. I went off of it when I went back to school and couldn't make it work. I would have liked to have the girlfriend excuse. :)
One really nice aspect of the system is that I was fully awake on Friday/Saturday night. I was learning how to dance at the time, being awake made that a lot easier.
On another note: this was a schedule I followed when I was in my early twenties. Now that I'm in my late 30's, following a conventional schedule is a LOT easier -- I'd never be able do this now.
Maybe that'll happen to me eventually. It wasn't a 28-hour cycle, certainly, but I've been on the overdrive until crash sleep schedule basically since I was born.
I don't see any end in sight. I have to stay up for almost 48 hours every few weeks when I actually have commitments (like a job) in the morning as a reset. It's annoying.
I did this without really planning it during my break between high school and college. I really enjoyed it, but it's not really practical if you have a "normal" family life.
It's kind of analogous to a lot of good software ideas, that would be amazing if only everything else were compatible.
The thing I don't like about alternate sleeping schedules is they usually include, as this one does, a warning to stick to it and go to bed at the set hours even if your not tired.
Personally if I was going to embark on this I wouldn't be very formal about the timing and just sleep when I got tired. I guess another thing that makes a big difference is if you have somewhere to sleep that you can make mostly dark during the day or will you frequently be going to sleep in a light room.
I had an officemate back in the mid 90s who was on this schedule for several years (he was a researcher able to set his own schedule for office time) and it worked quite well for him. He seemed to enjoy it and talked at length about how it was closer to the natural circadian cycle for people (which is a claim I don't know about.)
He did great work during that period; obviously this is just another anecdote but there you go.
It should be normal, which is the best part. The latter part of the experiment gets harder since you get more tired, so when it comes to going to bed in the normal 24 hour time, you should fall asleep like normal.
It's not hard to switch back and forth as long as you use one of the bedtimes that's normal for both schedules and just wake up with an alarm when you're supposed to on the new one.
The best thing about it was that I was actually tired (on the 20/8 variation) when it was time to go to bed, and I usually woke up a few minutes before my alarm starting on about the third day. These two phenomena never happen with any variation on a 24 hour day that I've tried. I was more productive (got my normal work done; started cycling regularly again; wrote more; and was averaging 2-3 books per week) and happier. I can't think of anything bad to say about it except that the last few hours of each "day" are a bit sluggish. I'm convinced that helped me sleep.
The only reason that I went off it was because my girlfriend has a fairly restrictive (yet changing) schedule. I was looking at not seeing her at all for a week if I continued it.
I should say that if I just go to bed when I'm tired, my body defaults to something pretty close to a 28-hour day regardless of light levels and the other people I've known to try it had negative experiences.