When I was quite young, my grandparents would travel from house to house on Christmas day, seeing their children and grandchildren at all the houses near enough to their St. Louis home to be visited in a long, full, jolly day. Later, this became pretty tiring for them and a few family members tried to persuade them to take it easy. But they were big big-family people (more than 30 grandchildren in the end) and they resisted. Finally, an idea was proposed that was satisfying:
On the morning of Christmas eve, they'd have open house at their house, and many of us would stop by. A couple of their daughters would make casseroles to serve as the core of the offering, and others would drop by with pastries or cookies or other potluck contributions. People would come when they could, stay for however long, and so the cast of folks around the big kitchen table changed all through the morning and into the early afternoon. Much coffee was poured, conversations shifted here and there around the table, and a suitable big-family tradition established itself in place of the previous one. By the time I was nearing adulthood, breakfast into brunch at my grandparents was as strong a family tradition as any other one we had.
More formally, the invention of tradition is a concept from the research of E. J. Hobsbawm, T. O. Ranger, Stephen Vlastos, and others. It appears that people reshape traditions all the time, sometimes then going on to assert that the new or updated traditions are as old as the hills.
See also, Fiddler on the Roof, "Tradition."