There has been no legal restriction on fasting and abstinence since 1959. Before that date, the usual rules were in effect. Some families kept the fasting, as in not eating between meals and having the two meals not equal the third, and the abstinence from meat for years and years.
I heartily encourage fasting and abstinence tomorrow in preparation for Christmas. It make sense to prepare for all the major feasts by penitence.
Because of parties and family gatherings, fasting and abstinence have all but disappeared from the Catholic culture since 1959. Such is progress...but I think not.
Curtailing eating helps us remember why we are here-in this vale of tears-to prepare for the coming of Christ in our lives and in the world.
The Eastern Catholics do a better job on this. Here is a list of their penitential days.
1. All Fridays of the year except when:
a. Great Feasts of the Lord or the Theotokos falls on a Friday
b. Period from Christmas to Theophany
c. From the Sunday of the Publican and the Pharisee to the Sunday of the Prodigal Son
d. Pascha to Thomas Sunday
e. Pentecost to All Saints Sunday
2. To abstain from meat and dairy products on the First Day of Lent and on Good Friday
3. Abstain from meat on
a. Day before Christmas and day before Theophany
b. Exhalation of the Holy Cross
c. Beheading of Saint John the Forerunner
Perhaps your family this year could try to abstain and fast this Christmas Eve. God bless you.