When I was in college, I discovered that after two semesters of the kind of thinking that helped me complete my course assignments, I’d itch for the kind of thinking that helped me consult for clients. And after a summer of practical-minded problem-solving, I’d be minded to float my head back up in the clouds.

When I graduated and got another programming job, I discovered that the kind of thinking I do to make worthwhile software energizes the kind of thinking I do to make worthwhile music. Once again, the converse also turned out to be true. On work-from-home days, I alternated between computer keyboard and piano keyboard as often as necessary to keep my code, and my brain, valuable and sustainable.

Chet Hendrickson recently reminded me that what we now call sustainable pace and had once called 40-hour week had originally been defined in XP as “no overtime”. These are not identical concepts. Overtime, as the XP folks meant it, meant “time spent in the office when you don’t want to be there”, or perhaps identically “time spent working that makes you less effective in the long run”. Maybe some people average 40 hours of wanting to be in their (real or virtual) office. Maybe some of them even cluster closely around 40 hours every single week. But there are plenty of us for whom 40 isn’t the average. And whatever your number is, no matter how closely you cluster around it, every now and then you need to take a zero.

I love my work, and I’ve enjoyed a cluster of completely terrific opportunities over the last couple months. But taken all together, they’ve taken altogether too much of my time away from the life my work is supposed to be a part of. By any definition, it’s been overtime. So last week and this week, I’m taking intentional zeroes. (Don’t worry, the writing of this post happened outside zero hours.) And when I get back into the swing of things, knowing myself, I’ll be energized to think and act to sustain my sustainable pace.