Manage your time or your energy

I’m a big advocate of time management, and have well over 100 posts on here about productivity of various forms. When you get down to it, though, your time isn’t what you need to manage — it’s your energy.
In the his book “ The Personal MBA “, author Josh Kaufman puts it this way:
Here’s the problem with “time management”: time is not what needs to be managed. No matter what you…