U.S. law (38 USC § 101, Definitions, line 29), which for purposes of benefits defines the “Vietnam era” as being
(a) February 28, 1961 to May 7, 1975 (for veterans who served in the Republic of Vietnam during that period) or
(b) August 5, 1964 to May 7, 1975 (for veterans who served outside the Republic of Vietnam during that period).
I made a mistake though, I watched it again and he didn’t call himself a “Vietnam era vet” but a “Vietnam time vet”.