This is a good, quick read for someone interesting in starting out with time management, prioritizing their life's activities, and wanting to understand the scriptural principles behind doing so.
It's not for someone who's already familiar with the biblical principles behind time management, and who's read a couple books on managing time. That's no knock of Perritt's book, it's not intended for that audience, it's intended for, say, a young father looking to get a handle on how to organize his life and time so he doesn't go nuts. That's probably the target audience, and it's a wonderfully accessible, readable, clear book for that.
Everybody can glean something of value from it, of course. I'm familiar with time management systems and tools, and the scripture behind the value of time, but I found value in this book. He's convicting without being accusing when discussing how Christians use their free time. I found that a particularly effective theme of the book, how so often we sacrifice more weighty, deep joys for trivialities.
Recommended for someone who wants a good handle on the biblical approach to time usage, and to start thinking about the blocks of time in their week. Doesn't offer a specific system or much practical instruction, but there are other books for that -- Matt Perman's "What's Best Next" and Tim Challies' "Do More Better," for instance.