Molly's Astrology. A few notes on Jupiter in Sagittarius. The planet Jupiter enters the sign Sagittarius on November 23, 2006, where he will stay until he enters Capricorn on December 18, 2007. Jupiter’s last journey through Sagittarius was December 1994 – January 1996. Before that, December 1982 – January 1984, January 1971 – February 1972, February 1959 – March 1960.