The first International Women’s Day was observed in 1911.
The observance followed a proposal made by Clara Zetkin at the Second International Conference of Socialist Women in Copenhagen in 1910. Zetkin called for an annual international day focused on women’s rights, especially voting rights and workplace equality.
The first major events took place on March 19, 1911, in Austria-Hungary, Denmark, Germany, and Switzerland. More than a million people participated in meetings, marches, and demonstrations. The date was not yet fixed as March 8.
That distinction explains a frequent quiz trap: 1910 was the year the proposal was made, but 1911 was the year the first International Women’s Day was actually held. March 8 became the regular date later, partly through its connection with the 1917 Petrograd demonstrations.