My experience at Google was that 20% time worked on the honor system. I'm not aware of anybody trying to measure it, nor do I know how you would. That said, I

My experience at Google was that 20% time worked on the honor system. I'm not aware of anybody trying to measure it, nor do I know how you would. That said, I think most people, most of the time did not take 20% time, so the real amount of time spent was probably much less than 20% averaged across the company anyway.