National Womens Day

9 August (South Africa)

National Women's Day commemorates 9 August 1956 when women participating in a national march petitioned against pass laws (legislation that required African persons to carry a document on them to ‘prove’ that they were allowed to enter a ‘white area’).
On this day in 1956 some 20,000 women marched to the Union [government] Buildings in Pretoria to protest against a law requiring black women to carry passes. This day is celebrated as a reminder of the contribution made by women to society, the achievements that have been made for women's rights, and to acknowledge the difficulties and prejudices many women still face
From an environmental perspective, women have played a leading role in many parts of the world in promoting sustainability. 

More info: http://www.info.gov.za/aboutsa/holidays.htm and http://africanhistory.about.com/library/bl/blsaholidays.htm