If you checked your copy of the 2020 Farmers’ Almanac, page 150 (December 2019 calendar page), or our Moon Phase calendar online, you saw that December’s Cold Moon turns 100% full on December 12th (12/12) at 12:12 a.m. Eastern Time. That’s a lot of 12s!
https://www.farmersalmanac.com/full-moon-december-2019-100914

