Jan 2018 had two full moons. 1/1 at 9:25 pm and 1/31 at 8:27 am
In our calendar, the dates of full (and new) moons will always fall 10-12 days earlier than the previous year. This is because 12 x 29.53 = 354.36 days, 10.64 days shorter than a regular year and 11.64 days shorter than a leap year. Slight differences due to speed of lunar orbit add a day or two to the differentials.
Now of course the full and new moons will be on similar dates in the Jewish calendar which is based on the Moon.