Day was a co-founder, and the founding president and general manager, of pioneer San Francisco public television station KQED, and in 1969 became the final president of National Educational Television (NET) before it closed operations in 1970, making way for its successor, the Public Broadcasting Service (PBS).
Day then became general manager of NET's now-former flagship, New York PBS member station WNET.
[1][2] One of Day's innovations at KQED was the local news program Newsroom, developed in response to a strike in early 1968 by San Francisco newspaper workers; Newsroom launched the careers of several broadcast journalists, and as the first nightly news program on a public television station, was considered a primary influence and forerunner to what is now PBS NewsHour.
He hosted two programs: Kaleidoscope while at KQED, and Day at Night, which he independently produced and syndicated after his 1973 resignation from WNET.
Among the numerous figures interviewed by Day were Eleanor Roosevelt, Aldous Huxley, Irving Howe, Eric Hoffer,[4][5] Ayn Rand[6] and Noam Chomsky.