(CNN) -- Friday is a day to celebrate and advocate for women.
Photo: International Women's Day
It's International Women's Day, and marches and rallies are planned around the globe.
The day officially goes back more than a century, to 1911.
Organizers say the day celebrates women's contributions to the world.
And it seeks to bring international awareness to gender inequality.
If you want to get involved, you can look up an event in your area, wear purple, and use the social media #InternationalWomensDay .