Apples and oranges. Individual Catholics may avail themselves strictly of the Saturday evening services. The Church itself does not only hold such services. If a Catholic Church held only a Christmas Eve Mass and none during the day on Christmas, that would be analogous. That isn't the case.
SD
I am sorry, I do not understand. If a member of your church goes on the 24th, Chrismas Eve, must he then go on the 25th, Chrismas Day ?