A lot of squares and a lot of adjusting this month. Here is a breakdown of the mutable squares and conjunctions to Pluto in Capricorn. Check the December Astro Perspective for analysis:
Dec 4 - Mercury in Sag square Uranus in Pisces
Dec 6 - Mercury in Sag square Saturn in Virgo
Dec 10 - Sun in Sag square Uranus in Pisces
Dec 11 - Mars in Sag square Uranus in Pisces
Dec 12 - BIG DAY! Full Moon in Gemini forming mutable Grand Cross, Sun in Sagittarius square Saturn in Virgo, Mercury conjunct Pluto at 1 degree Capricorn
Dec 15 - Mars in Sag square Saturn in Virgo (final mutable square and the effect of the mutable T-Square loosens)
Dec 22 - Sun conjunct Pluto at 1 degree Capricorn
Dec 27 - New Moon in Capricorn
Dec 28 - Mars conjunct Pluto at 1 degree Capricorn
Squares are tense aspects of two very different energies having to deal with each other and work together, but astrology allows us to be forewarned and forearmed about these sometimes sticky aspects.
The conjunctions to Pluto at the beginning of Capricorn can also be difficult, but being aware that certain power struggles and authority issues can arise those days (and become explosive unless negotiated well) does a lot for us.
You can think of the planets in Sagittarius moving to conjunction with Pluto in Capricorn as being in Balsamic phase. Like the Balsamic phase of the Moon each month (or Dark of the Moon). This means that we'll be purging and shedding any remaining Sagittarian issues as the planets pass through the final degrees of Sagittarius and conjunct Pluto in Cap.
These days of ending the old phase (connected to the entire process of Pluto in Sagittarius) are Dec 11, 21 and 27.