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 4 was the second crewed mission of the NASA's Project Gemini. The mission was commanded by Command Pilot James A. McDivitt and Pilot Edward H. White II. On the mission, White became the first American to perform a spacewalk. The mission began on June 3, 1965, 15:15:59 UTC and ended on June 7, 1965, 17:12:11 UTC.
NET: June 3rd 1965 - 15:15 UTC
Instantaneous launch window.