I like the concept and I personally use variations of it. However, I find that 30/30 is not only the wrong ratio (1:1) but also the lengths don't work too well

I like the concept and I personally use variations of it. However, I find that 30/30 is not only the wrong ratio (1:1) but also the lengths don't work too well for certain types of activities. c.f. http://www.paulgraham.com/makersschedule.html http://www.paulgraham.com/makersschedule.html