There is an xkcd strip for this: http://xkcd.com/320/

I always thought that it was a joke, but you can seriously try it and tell us how did it work.

Is anyone actually living with this? [1] A circadian rhythm of 28 hours sounds quite rare.

1: http://www.dbeat.com/28/

I did that for most of a 4 month period and several other smaller stretches about 15 years ago. It worked great for me at a time.

As I've gotten older, it's become easy to fall asleep and wake up when I want to. Two things are critical to that:

1) no screen time in the 2 hours before bed. No TV, no computer. The only exception is reading books on my phone in night mode at the lowest setting.

2) no caffeine except for small amounts of chocolate.

My wife teases me because I can fall asleep in under a minute, and taking more than 10 minutes to fall asleep is actually one of the signs of a sleep disorder. (I don't have any of the other signs). It's not normal, but no TV or computer at night and no caffeine are not normal, either.

I did it for a few months while writing up my Ph.D., and I wish I could continue, but various commitments mean I'm stuck with 7x24. 6x28 suited me very well, felt much better than I do on 7x24.

Cool! Have you tried free running sleep to measure your natural circadian rhythm? [1,2]

1: http://en.wikipedia.org/wiki/Free-running_sleep

2: http://www.supermemo.com/articles/sleep.htm#Free running sleep

Haven't got the chance - would love to do so. No blocks of two weeks without fixed time commitments.

I live with something approximately close.

Having an office to go into and coworkers to be accountable to is the only thing that keeps me sane.