Declared Periods of War

World War II: December 12, 1941 to December 31, 1946

Korean Conflict: January 27, 1950 to January 31, 1955

Vietnam War: August 
5, 1964 to May 7, 1975
February 28, 1961 to August 5, 1964
for those who served in the country of Vietnam

Gulf Conflict Era: August 
2, 1990 to present 

Veterans only need to have served one day of active duty during a declared period of war and a minimum of 90 days of active service, to be eligible for this benefit. 

Reservist are eligible if they were called up to duty during the declared period of war. Training does not count as active service.

Service after 1980 must consist of 24 months of active duty and the veteran must have completed his tour of duty.