What Christmas traditions have roots in Jewish traditions? There are many traditions in modern Christmas celebrations, that Jesus would not be familiar with.

What Christmas traditions have their roots in Jewish celebrations, that Jesus would recognize?
The Feast of the Circumcision of Jesus is a Christian celebration of the circumcision of Christ in accordance with Jewish tradition.

This feast is celebrated by Catholics who follow the Extraordinary Rite of the Mass on January 1st. The feast is celebrated on the octave day of Christmas, thus concluding the ancient tradition of celebrating major feast days (Christmas, Easter and Pentecost) for eight days.  This is also the day that Jesus received his Most Holy Name. 

There is also the Feast of the Holy Name of Jesus , which is celebrated on another date than on January 1st in the Roman Catholic Church.


  The Feast of the Holy Name of Jesus is a feast of the liturgical year celebrated by a number of Christian denominations, on varying dates. In Roman Catholicism the month of January is traditionally dedicated to the Holy Name of Jesus.
  
  In the Latin Rite Catholic Church it is observed as an optional memorial on 3 January by Catholics following the present General Roman Calendar. Franciscans, Carmelites, and Augustinians kept the feast on 14 January; Dominicans on 15 January; in some localities the date was 8 January, in others 31 January, in some localities in Great Britain on 7 August. The Society of Jesus, i.e., the Jesuits, celebrates the Holy Name of Jesus on 3 January as the order's own titular feast.