The Titan II GLV (Gemini Launch Vehicle) or Gemini-Titan II was an American expendable launch system derived from the Titan II missile, which was used to launch twelve Gemini missions for NASA between 1964 and 1966. Two unmanned launches followed by ten manned ones were conducted from Launch Complex 19 at the Cape Canaveral Air Force Station, starting with Gemini 1 on April 8, 1964.WIKI
Gemini 6A was the fifth crewed mission of the NASA's Project Gemini. The mission was commaned by Command Pilot Walter M. Schirra, Jr. and Pilot Thomas P. Stafford. The mission achieved the first rewed rendezvous with the Gemini 7 spacecraft. The mission began on December 15, 1965, 13:37:26 UTC and ended on December 16, 1965, 15:28:50 UTC.
NET: December 15th 1965 - 13:37 UTC
Instantaneous launch window.