Many young Jews do not know of Shabbos in the biblical sense – as cessation, as full stop, as committing to one particular place – even as an outmoded vestige of a distant past. They have simply never heard of it. When introduced, it comes as a revelation.

In its celebration of self-discipline, secular Sabbatarianism has a surface resemblance to the Orthodox and Puritan Sabbaths, but it has a deeper affinity to other, recent movements in which Americans take themselves off the grid: the voluntary simplicity movement, the green or sustainability movement, the frugality movement.