March 8 marks International Women’s Day – a day the United Nations says is “a time to reflect on progress made, to call for change and to celebrate acts of courage and determination by ordinary women.”

Sure, sounds pretty good. But why do we have International Women’s Day in the first place? Here’s more about this particular commemorative day.

How did International Women’s Day start?

There seems to be a bit of disagreement on what exactly constituted the first Women’s Day, but there’s no disagreement on one thing: historically anyway, it was really socialist.

According to the UN, the first National Women’s Day happened in the United States on Feb. 28, 1909 and was organized by the Socialist Party of America to honour the 1908 garment workers’ strike in New York.

The idea for an international Women’s Day was adopted in Copenhagen by the Socialist International in 1910, and was first celebrated in Austria, Denmark, Germany and Switzerland on Mar. 19, 1911. People marched to express support for women’s suffrage and to end discrimination at work.

The first time it was celebrated on Mar. 8 was in 1917, when Russian women protested for “Bread and Peace” against the backdrop of WWI. Just days later, the Czar abdicated and the provisional government granted women the right to vote.

Vladimir Lenin made the day an official holiday in the Soviet Union in 1922, and over the next few decades it was celebrated mostly in communist countries, including China, where women are given a half day off from work even today.

The United Nations brought the idea back to the western world in 1975, when it celebrated International Women’s Year and adopted the same celebration date as the communist countries.

Since the 1990s, the UN started adopting an annual theme for the day.

What’s this year’s theme?

In 2016, the official theme is “Planet 50-50 by 2030: Step It Up for Gender Equality.”

The idea is to push for measurable gender equality, particularly when it comes to education.

How far away are we from that?

Depends who you ask, but most would say pretty far. Even the United Nations, which tends to be optimistic, is only hoping that things like equal access to education and an end to gender discrimination happen by 2030.

To give just one recent Canadian example, a new report from Oxfam Canada and the Canadian Centre for Policy Alternatives estimated that in 2011, women earned 72 cents for every dollar men earned. It’s partly due to more women working part time – many of them saying that they only work part-time because of concerns about child care.

READ MORE: Pay equity laws not a silver bullet, Status of Women minister

An international report from January on women at work called the situation “an economic and social travesty.”

And that’s just employment – there are lots of other ways to be discriminated against. For example, women also face higher rates of family violence, according to police-reported crime numbers from Statistics Canada.

Is there an International Men’s Day?

Actually, yes. It’s Nov. 19. It’s not as old an event though, and it doesn’t seem to be backed by the UN the same way Women’s Day is.

You can still celebrate it though: the campaign has a particular focus on men’s health and highlighting positive male role models. 2015’s theme was “Expanding Reproductive Options for Men.”