WASHINGTON (CNN) — International Women’s Day is set to take place on Wednesday, March 8, an annual marker that aims to bring attention to women’s accomplishments and obstacles.

But this year, the day comes amid an already contentious political environment, where protesters have turned out in force to voice disagreement with the new administration’s policies and President Donald Trump’s rhetoric, especially regarding women’s issues.

Here’s what you need to know about International Women’s Day:

What is it?

The day is designed to “reflect on progress made, to call for change and to celebrate acts of courage and determination by ordinary women who have played an extraordinary role in the history of their countries and communities,” according to the United Nations’ website.

The first International Women’s Day took place in 1911 in Austria, Denmark, Germany and Switzerland, according to the International Women’s Day website.

Who is participating?

Companies including Avon, BP, PepsiCo and Caterpillar are all International Women’s Day partners, according to the website.

Separately, there are some individuals who planning to take part in a national women’s strike called “A Day Without a Woman” — which has garnered support from the organizers of the Women’s March on Washington — that is scheduled to take place on International Women’s Day.

Pop singer Katy Perry and comedian Amy Schumer have both posted in support of the strike on social media.

“Standing with all my sisters in solidarity! Gonna be a lady in red tomorrow,” Perry tweeted.

“Let’s rock #adaywithoutawoman tomorrow,” Schumer posted to Instagram.

A number of businesses that say they plan to observe the day in some fashion, including by closing up shop due to a lack of workers. Multiple school districts surrounding DC, including Alexandria Virginia Public Schools and Prince George County Schools in Maryland will be closed, according to the schools’ websites.

What events are taking place?

There are numerous events scheduled around the world intended to bring attention to International Women’s Day.

You can find information on specific events here.

Additionally, for those looking to support the general strike, the Women’s March on Washington has three specific action items on how to do so: women take the day off from work, only shop at “small, women- and minority-owned businesses” and wear red in solidarity.

A rally is also scheduled in New York City, at 12 p.m. ET at the intersection of 5th Avenue and 59th Street, according to the Women’s March website.