Women all around the world celebrate March 8 every year to affirm their political, economic, social, cultural and other rights.
Two important events at the beginning of the 20th century paved the path for the international recognition of this day. In 1908 15 000 women march through New York demanding shorter working hours, better wages and right to vote. Two years after, in 1910 in Copenhagen women’s conference was held organized by the Second International where Clara Zetkin proposed the establishment of 'International Women's Day'.
After the October revolution it was proclaimed the national holiday in USSR. It was celebrated in 1920s in the West, after which it lost its popularity. However, with the revival of women’s liberation movement in the 60s it gained widespread popularity and today it is celebrated in most countries of the world.

The following article, published by Worldwatch Institute, provides us with some alarming numbers and examples : http://www.worldwatch.org/node/1720