In the traditional church calendar, the Nativity is celebrated on Dec. 25, the Circumcision 8 days later on Jan. 1, and the Presentation in the Temple (or the Purification of the Virgin Mary) on Feb. 2, the 40th day after the Nativity.
Mary and Joseph were observant Jews, Jesus would have been circumcised when he was eight days old, Joseph would have named Him, and there would have been a sacrifice.
I have know idea what your dates are referring to, the family would have acted in accordance to the Law.