Workers, however, were upset. One of them openly complained to Pravda: “What are we to do at home if the wife is in the factory, the children in school, and no one can come to see us? What is left but to go to the public tea room? What kind of life is that—when holidays come in shifts and not for all workers together? That’s no holiday, if you have to celebrate by yourself.”

The staggered workweek didn’t last long. Officials worried that it affected attendance at workers’ meetings, which were essential for a Marxist education. In 1931, Stalin declared that the nepreryvka had been implemented “too hastily,” leading to a “depersonalized labor process” and the mass breakage of overtaxed machines. That year, the government added a day of collective rest. The seven-day week was not restored until 1940.

Experiments like this one have given social engineering a bad name. Nevertheless, Americans are imposing a kind of nepreryvka on ourselves—not because a Communist tyrant thinks it’s a good idea but because the contemporary economy demands it. The hours in which we work, rest, and socialize are becoming ever more desynchronized.

Whereas we once shared the same temporal rhythms—five days on, two days off, federal holidays, thank-God-it’s-Fridays—our weeks are now shaped by the unpredictable dictates of our employers. Nearly a fifth of Americans hold jobs with nonstandard or variable hours. They may work seasonally, on rotating shifts, or in the gig economy driving for Uber or delivering for Postmates. Meanwhile, more people on the upper end of the pay scale are working long hours. Combine the people who have unpredictable workweeks with those who have prolonged ones, and you get a good third of the American labor force.

The personalization of time may seem like a petty concern, and indeed some people consider it liberating to set their own hours or spend their “free” time reaching for the brass ring. But the consequences could be debilitating for the U.S. in the same way they once were for the U.S.S.R. A calendar is more than the organization of days and months. It’s the blueprint for a shared life.

Remember the old 9-to-5, five-day-a-week grind? If you’re in your 30s or younger, maybe not. Maybe you watched reruns of Leave It to Beaver and saw Ward Cleaver come home at the same time every evening. Today few of us have workdays nearly so consistent. On the lower end of the labor market, standing ready to serve has become virtually a prerequisite for employment. A 2018 review of the retail sector called the “Stable Scheduling Study” found that 80 percent of American workers paid by the hour have fluctuating schedules. Many employers now schedule hours using algorithms to calculate exactly how many sets of hands are required at a given time of day—a process known as on-demand scheduling. The algorithms are designed to keep labor costs down, but they also rob workers of set schedules.