At the height of the pandemic, most working Americans spent at least a few weekdays at home. Some were laid off, some were working remotely, but most had one thing in common: They were suddenly spending long hours inside a single house or apartment with the same few family members.

It will stand as one of the fastest, most sweeping shifts of human behavior in modern history.

At one point, almost half the population spent more than 18 hours a day in their homes, according to the location-data provider SafeGraph. The people we usually see most during waking hours — our co-workers — were replaced by our spouses and children. The places we see most — workplaces, bars, grocery stores — were replaced by extended hours in our homes.

We’re still sifting through the economic and psychological fallout. The data shows Americans gained far more free time and used it to care for children while exercising and working more. But they also devoted a massive amount of time to watching more television. At the same time, many relationships are facing strain from the stress of concurrent economic and public-health disasters. And the pandemic appears to have been particularly tough on the happiness of singles, especially women, research suggests.

As shutdowns peaked in March and April, the daily 7 a.m. flow out of the house dried up. At any given point in the day, most people were inside their homes or yards.

They usually had company. Of almost 90 million American adults whom the Labor Department classified as being forced home by the coronavirus pandemic for at least some of May:

  • About 1 in 8 were home alone.
  • Almost 2 in 5 were home with kids.
  • Almost half were in a household with another adult who was also suddenly sent home.
  • More than two-thirds were home with another adult, such as a stay-at-home spouse or retiree.

These figures have fallen since May, but still describe millions and millions of people who spend each day within a narrow pandemic social circle.

Every year, the government solicits thousands of time diaries from a representative sample of Americans. People record what they’re doing, from bowling to budgeting. They also note whom they’re with and where they are.

The pandemic has interrupted and probably delayed the distribution of 2020 data, but when we look at pre-pandemic time use data, we see our four most common activities outside the home on weekdays — working, commuting, visiting restaurants and bars, and socializing — were actions that would be drastically altered by the novel coronavirus.

Some of those activities, such as eating, have been replaced with an at-home equivalent. But others, such as commuting, represent new blocks of free time. Those don’t arise often, especially at this scale, and we can learn quite a bit from how folks chose to spend it.

Economist José María Barrero of the Autonomous Technological Institute of Mexico and his collaborators asked almost 5,000 Americans how they used the time they saved by not commuting. Almost half (44 percent) of those time gains have been devoted to additional work, but folks also watched more television, took care of their kids, did chores and even exercised. Parents are more likely to spend their saved time on child care; non-parents are more likely to spend it on more work and television.

The nonwork categories that gained the most — child care, television and eating — are also the ones on which working-age (25-54), married Americans spent most of their pre-pandemic together time, Labor Department data shows. Television took up more than half of a typical couple’s together time, and almost a fifth of the time parents spent with their children.

“Even before the pandemic, Americans — especially older Americans — watched a lot of TV,” said American University economist and time use researcher Gray Kimbrough. “We probably watch significantly more now, but it was already really high. I feel like people think a lot about eating at restaurants and socializing outside of the home, but I’m pretty sure that these were dwarfed by sitting on the couch watching TV.”

Even before we know precisely how much together time American couples gained during the pandemic, we can guess the shift dwarfs any other in memory. When asked, economists struggled to name a previous time when our daily patterns shifted so suddenly. One suggested the Black Death that swept through Europe, the Middle East and North Africa in the 1340s and 1350s. Others mentioned the industrial revolution, the 1918 pandemic or World War II.

A Washington Post analysis of historical time use data dating back to 1965, the earliest date for which comparable figures are available, showed that the share of the workday we spend with our spouses has changed little over that time. But the pandemic shredded previous patterns by removing or shortening commutes, forcing millions out of work and increasing child-care burdens. Experts say we can only guess at the potential short- and long-term effects of a cataclysm with so little precedent.

In normal times, spending more hours around our spouses each week would make us happier. Barnard College economist Daniel Hamermesh, author of “Spending Time,” has found that happiness rises as couples spend additional time together. A study of time use in the Netherlands calculated that couples were willing to sacrifice about a tenth of their hourly earnings to synchronize their schedules — though the burden fell unevenly.

“Women are most likely to restrict the timing of their paid work and their flexibility in the labor market in order to realign their schedule with their husbands,” said Alexandros Theloudis, an economist at the Luxembourg Institute of Socio-Economic Research and one of the authors of the analysis.

Although we don’t have nationally representative data, economists Tatyana Deryugina of the University of Illinois at Urbana-Champaign, Olga Shurchkov of Wellesley College and Jenna Stearns of the University of California at Davis recently analyzed time use information from almost 20,000 academics worldwide.

Even before the pandemic, they found, women in academia spent about 50 minutes more each day caring for children and doing other household tasks, but nonetheless worked almost as much as men. The pandemic decreased the research work these women did by about an hour, and increased their child-care and housework burden by more than two hours. Men in academia saw a smaller increase in child care and housework time (about 90 minutes).

“Gender gaps among academics, both in terms of status and productivity, have been large even before the onset of covid-19,” Shurchkov said. “The loss of research time due to the unequal sharing of parental responsibilities could mean that women fall even farther behind.”

“In the long run,” she said, “the implication could be that women with young children may be disproportionately less likely to be promoted in rank and perhaps even more likely to drop out of academia altogether.”

A Washington Post analysis of Bureau of Labor Statistics monthly data on marriages, separations and divorces shows few substantial changes thus far, though many signs point to a post-pandemic rise in separations and divorces. But it’s hard to attribute any rise in divorces to an increase in togetherness. Couples are going through astonishing levels of stress right now. They’re losing jobs and income, and coping with the deaths of more than 475,000 friends and relatives.

“If you see those two people fighting with one another, I’m not sure you could blame additional togetherness for that, because all sorts of other things are happening at the same time,” Theloudis said.

But although it’s likely that the quantity of togetherness has changed, it’s also likely that the quality of our hours together has decreased, Hamermesh said.

“We’re doing much more streaming of television now than we used to,” Hamermesh said of himself and his retired spouse. “But to me, that’s simply a substitute for the commuting time, the shopping time — also to some extent going to the theater, to movies, to the opera, which is togetherness, also. The streaming is a poor substitute.”

The steepest consequences, Hamermesh said, will fall on the folks who are stuck at home alone. Singles start with lower life satisfaction than married couples do, and it falls significantly as they spend more time alone.

Isolation, such as that enforced by pandemic shutdowns, has been shown to take a particularly high toll on single women. Hamermesh’s work shows the decrease in single women’s happiness will have been compounded by their increased likelihood of losing work and income during the pandemic shutdowns — especially if they are the only caregiver for a few young children.

“They’re isolated and they have the kids at home,” Hamermesh said. “This, I think, is the real disaster.”

The Post’s Akilah Johnson explains the challenges the Biden administration faces to distribute the vaccine to low-income, vulnerable communities equitably. (Joy Yi/The Washington Post)