I thought you was BSn us. I checked and I will be danged. The celebration starts the end of this month and goes until the 10th of Jan. The Christmas day is Jan 7th.
Learn something new every day.
As an Orthodox Christian I need to live by two calendars...Julian and Gregorian.
Fortunately in most of North America the Gregorian will suffice but in relating to some Slavonic/Russo Orhtodox communities one needs to be aware that they are thirteen days “behind”.