There are two main issues with this sleep schedule: 1) Getting home at 5 (not likely with a job in the US, especially with a startup-job like the one I had in

There are two main issues with this sleep schedule: 1) Getting home at 5 (not likely with a job in the US, especially with a startup-job like the one I had in the valley, where performance often seems to be measured mainly by the amount of time one is physically present in the office each day) 2) Most of social life happens in the evening, even over the weekend. I guess one could get away with it in the Netherlands, or other countries where bars stay open all night, and many only start going out around midnight (one could become known as the ultimate party animal by being fully awake while others are getting sleepy around 4 AM... ;-) Finally, I did try a similar sleeping schedule for a week when I was hiking on Frazer island in Australia. To conserve the batteries of my flashlight I went to bed at sundown (around 7pm) and up with sunrise (around 4am), and I rarely felt more well-rested... But yes, due to synchronisation issues with others circadian rythms I don't think radical sleeping schedules will become common soon...