I worked in a wafer fab for a summer and we did four 12 hour days and then three days off. And then three days of work and four off.<p>It was by far one of my favorite schedules. I rode my bike to work and that was about 45 minutes each way and when you add in the time it takes to get ready for work it was nice to only have to do that 50% of my days. And with four day breaks I was able to really get into projects or go camping for a long time.