Jan 30, 2018 is the fifty-year anniversary of the Tet Offensive of the Vietnam War.

"was one of the largest military campaigns of the Vietnam War, launched on January 30, 1968, by forces of the Viet Cong and North Vietnamese People's Army of Vietnam against the forces of the South Vietnamese Army of the Republic of Vietnam, the United States Armed Forces, and their allies. It was a campaign of surprise attacks against military and civilian command and control centers throughout South Vietnam"

https://en.wikipedia.org/wiki/Tet_Offensive