Now, Nick Bloom, Stanford economics professor and head of WFH Research—a group that has been digging into remote work data since before the pandemic—has officially deemed Roth correct. 

“Friday has become the day to #wfh,” Bloom tweeted on Friday, adding that it “looks like [Steven Roth] was right.” But as always with Bloom and his vaunted remote work research, there is more to the story.

Despite the fact that offices have been completely desolate on Fridays for over three years now, Bloom told Fortune that he was nonetheless surprised that Roth’s prediction has ended up bearing out. “I thought this would be more stable, but I guess…Friday [is] increasingly winning out in the WFH stakes,” Bloom told Fortune by email on Friday. “I think it’s part of the bigger push towards coordinated hybrid, whereby we have firms pushing for folks to come in on the same days.”

In-person socializing and collaboration, as always, is the main appeal for office work. As a result, Bloom said, it makes sense to coordinate with one’s coworkers, among whom the consensus has been made clear: “That includes coordinating to be home on Friday.” Indeed, coordinating in-office days among teams is the best way to pull off “organized hybrid,” the term Bloom uses to describe the gold standard working arrangement.

The new Friday calculus shows Bloom that there is now a “three-part week,” he tweeted. Mondays through Thursday are one thing, the weekend, when offices are closed, is another—and then there’s Friday.

Back-to-work mandates rarely include Friday 

While it’s certainly unlikely that cubicles will ever be populated on Saturdays and Sundays, Fridays may still have a fighting chance—especially given how many major corporations have finally put their foot down about returning to the office. For years, many high-profile companies have faced fierce resistance from employees they’ve ordered back to work. 

Amazon instituted a three-day minimum for in-person work back in February. The policy faced its latest snafu earlier this week when some employees got a disciplinary email even though they’d been complying with the new rules. Google also has a policy of a mandatory three days in the office, and will reportedly only consider full-time remote work in exceptional circumstances. 

Meanwhile, Salesforce upped the ante even further, with an obligatory four days in-person for some teams. Based on Bloom’s research one might suspect the lone work-from-home day for Salesforce employees might naturally be Friday. 

Bloom also has data to back up that employers and employees don’t see eye to eye on the number of days they’re meant to be in the office. On average, there’s about half a workday’s difference between the number of days workers would like to be in the office compared with what their bosses expect—or require, WFH Research has found. 

Per a recent report from real estate consulting firm JLL, bosses have mandated a return (at least some days per week) for 1.5 million workers, and another million are set to be given the same threat in the back half of this year. 

Even though more and more companies are beginning to formalize exactly when employees are allowed to work from home, the practice remains widespread. An estimated 58% of workers—a figure that when extrapolated to the entire U.S. workforce would be equal to 92 million people—can work remotely some days of the week, per June research from McKinsey. Naturally, the fact that at least one of those days will be Friday is all but a given.