In 1929, the Soviet Union replaced the seven day week with the or “continuous working week”.

Workers were split into five groups on five-day cycles with staggered rest days so that production never stopped. It became common for people to colour-code their friends in their address books according to which day they had off.

It wasn’t popular.

“What is there for us to do at home, if our wives are in the factory, our children are at school and nobody can visit us?” one worker complained in a letter to a newspaper.

As Oliver Burkeman, who writes about the nepreryvka in his new book , observes: “The value of time comes not from the sheer quantity you have, but from whether you’re in sync with the people you care about most.”

The Soviet Union abandoned its vast experiment after 11 years.

But today’s economy is moving back towards a sort of “continuous working week”. Society’s shared rhythms of daytime work and weekend rest are disintegrating before our eyes.

The decline of the “9 to 5” has been under way for decades.

In 2010-11, 20 per cent of employees in the United States worked more than half their hours outside the standard hours of 6am to 6pm or on weekends.

A vast survey of workers across the European Union (EU) in 2015 found about half worked at least one Saturday a month, almost a third worked at least one Sunday, and roughly a fifth worked at night.

As in the Soviet Union, one driver of these working patterns has been the desire of manufacturers to run plants 24/7 to maximise the use of machines and minimise the cost of interrupted production.

One common shift pattern for production and warehouse workers today is to work four 12-hour days, have four days off, then work four nights, then have another four days off.

Another is to work eight-hour shifts on rotation.

As one current United Kingdom job advert for a warehouse job explains: “The hours of work are: 6am to 2pm, 2pm to 10pm, 10pm to 6am. You will work one week on one shift and then rotate, therefore flexibility to cover all shifts is required.”

Factories and warehouses aren’t the only workplaces that run around the clock.

Shift work is common for doctors, nurses, carers, drivers and security guards, among others.

It appears to be on the rise. In 2015, 21 per cent of workers in the EU reported doing shift work, up from 17 per cent a decade earlier.

While shift work suits some people, the evidence suggests it damages their health, especially if they rotate between days and nights.

Twelve-hour shifts, rotating shifts and unpredictable schedules are associated with higher risk of mental illness, cardiovascular problems and gastrointestinal problems.

Shift work can also harm family life.

“Divorce is pretty bad. We see a lot of divorce, just due to the fact that families, especially young couples, you’re away from your family [for] 12 hours, and then when you go home after a 12-hour shift, you just want to sleep,” one manager in a US manufacturing plant told academics studying the impact of shift work.

A worker in the same study said: “It changes our time with our family. It changes our time with our social life and church and community groups. All those things that you would like to be involved with.”

The old work rhythms are breaking down in office life too, but in this case it’s driven more by employees.

The spatial freedom to work outside the office, supercharged by the pandemic, has increased the temporal freedom to work at any time.

“Asynchronous work” is the new buzzword in human resource and management circles.

This has advantages: it avoids the unpleasant synchrony of everyone cramming on to trains every morning and evening, and allows people to fit work around other priorities or responsibilities.

There are downsides too.

A study published in 2017 of workers in 15 countries found that the impact of remote work on work-life balance was “highly ambiguous”: Workers reported more time with their families, but also an increase in working hours and blurred boundaries between paid work and personal life.

Regulators are already thinking about how to protect white-collar workers. France and Mexico, for example, have promised a “right to disconnect” from emails and phones.

But policymakers should pay more attention to shift workers, too, whose employer-dictated hours can be out of sync with their body clocks and family lives.

The disintegration of the old working week creates winners and losers.

One of the stark divides in the post-pandemic world will be between those who can fit work around life, and those who must fit life around work. FINANCIAL TIMES

ABOUT THE AUTHOR:

Sarah O'Connor is a columnist, reporter and associate editor at the Financial Times. She writes a weekly column focused on the world of work.