December 2016 New & Full Moons: Full Moon in Gemini & New Moon in Capricorn Nov 16, 2016 · A full moon occurs on December 13th at 7:06PM ET in Gemini, and full moons in Gemini are usually good times to merge together the heart and the mind. Full moons are emotional and Gemini is the sign of the mind, so we can express what we feel, think about our emotions, and bring together the logic of what we know with the instincts of our hearts.