Martyrs' Day (Azerbaijani: Qara Yanvar) is a national holiday in Azerbaijan. It may also be known as 'the Day of the Nationwide Sorrow'.
It is observed on 20 January. Since 2006, if the 20 January falls on a weekend, the following Monday will be a holiday.
In January, 1990, the Armenian SSR voted to include Nagorno-Karabakh (a region within Azerbaijan) in its budget, allowing the people in the region to vote in Armenian elections.
This was seen as an attempt by Armenia to replace Azerbaijan’s jurisdiction of its own territory. The move enraged the Azeris, which led to large demonstrations in Baku demanding separation from the Soviet Union.
By this time, cracks in the Soviet Union had already started to appear and the Soviets fearing these protests would further threaten more threaten the Union, tried to quell the protests with military force.
On 19-20 January, the Red Army entered Baku and shot dead over 130 civilians.
These actions only served to strengthen Azerbaijani opposition to the Soviet Union, and was a key catalyst in the movement for independence, which happened with the end of the Soviet Union in December 1991.
The massacre of the civilians became known as Black January, also known as Black Saturday or the January Massacre.
This holiday remembers those events and the sacrifices of the civilians. The day also remembers the victims of the Nagorno-Karabakh War (1988 - 1994) between Azerbaijan and Armenia.