Daily staff journal
Item 19 on this daily staff journal documents the exact time when Neil Armstrong walked on the Moon—11:03 A.M. The entry was made by a soldier in the 101st Airborne Division’s 2nd Brigade stationed near Hue, Republic of Vietnam. Because Vietnam is on the other side of the International Date Line, the date is 21 July 1969 (instead of July 20).
National Archives, Records of the U.S. Forces in Southeast Asia