We can also easily translate the lesson across cultures. If women in the United States had staged the same protest, for example, they would have left work at 2:12 PM. In South Korea, it would have been 12:36 PM. In Pakistan, 10:50 AM.

Plus, since women’s-rights organizations and labor unions in Iceland have organized the demonstration in the past, we can actually measure, in minutes, the country’s advances on pay equity. On October 24, 2005, women in Iceland left work at 2:08 PM. On October 24, 2010, they departed at 2:25.

It’s encouraging that progress has been made. But the pace of that progress is dispiriting nonetheless. On Monday, women in Iceland left work only half an hour later than they did 11 years ago. If “the same trend continues,” Vala Hafstad writes in Iceland Review, “not until 2068 will women and men enjoy equal pay.”

The struggle, moreover, began well before 2005. On October 24, 1975, 90 percent of women in Iceland—that’s nine with a zero after it—went on strike to campaign for equal rights. The BBC has more on that extraordinary day:

It is known in Iceland as the Women’s Day Off, and [Vigdis Finnbogadottir, Iceland’s first female president] sees it as a watershed moment. ... Banks, factories and some shops had to close, as did schools and nurseries—leaving many fathers with no choice but to take their children to work. There were reports of men arming themselves with sweets and colouring pencils to entertain the crowds of overexcited children in their workplaces. Sausages—easy to cook and popular with children—were in such demand the shops sold out. It was a baptism of fire for some fathers, which may explain the other name the day has been given—the Long Friday. “We heard children playing in the background while the newsreaders read the news on the radio, it was a great thing to listen to, knowing that the men had to take care of everything,” says Vigdis. … “Things went back to normal the next day, but with the knowledge that women are as well as men the pillars of society,” she says. “So many companies and institutions came to a halt and it showed the force and necessity of women—it completely changed the way of thinking.”

Yet here Iceland’s women were, in Austurvollur square exactly 41 years later, yelling Ut. What’s most sobering about Monday’s rally is that it occurred in what is arguably the most gender-equal nation on earth. Iceland has had either a female president or a female prime minister for 20 of the last 36 years. Every year for the last eight years, Iceland has finished first among 100-plus countries in the World Economic Forum’s annual Global Gender Gap ranking, which quantifies disparities between men and women in health, politics, education, and employment (the higher a country’s ranking, the smaller its gender disparities).