International Women's Day (IWD) is marked on March 8 every year. It is a major day of global celebration for the economic, political and social achievements of women.
Started as a political event, the holiday blended in the culture of many countries (primarily Russia and the countries of former Soviet bloc).
In some celebrations, the day lost its political flavour, and became simply an occasion for men to express their love to the women around them in a way somewhat similar to Mother's Day and St Valentine's Day mixed together. In others, however, the political and human rights theme as designated by the United Nations runs strong, and political and social awareness of the struggles of women worldwide are brought out and examined in a hopeful manner.
The IWD is also celebrated as the first spring holiday, as in the listed countries the first day of March is considered the first day of the spring season.

Source: Wikipedia