World Humanitarian Day: 19 August

The World Humanitarian Day is observed across the world on August 19 to pay tribute to workers who risk their lives in humanitarian services and to gather support for people affected by crises around the world. The campaign launched on World Humanitarian Day is “#NotATarget”. 
The day was designated by the UN General Assembly to commemorate the 19 August 2003 bombing of the United Nations headquarters in Baghdad, Iraq.

Source- The United Nations