This book seems to be really derivative.

Chapter 1 seemed to be a rehash of Heschel's "The Sabbath: Its Meaning for Modern Man", a classic book on Jewish Shabbat that I've also read.

He doesn't really provide anything new to the conversation about personal observance of the Sabbath, except that he puts it in terms that someone unfamiliar with Judaism can understand and says that you could observe a Sabbath at any time and while doing things that you find personally meaningful.

Find things that are meaningful to you and dwell on them in a meditative way is how I would sum this up so far, and there's nothing wrong with that I suppose, but the way the author presents it as if he's telling us something new and original, when it's not. He's, so far, simply borrowing from Christianity, Judaism, and Buddhism.