Another Christmas tradition is our Christmas Eve meal.
When I was growing up, I remember my mom preparing a Christmas Eve dinner (usually ham). My grandparents and my aunt's family would come to our house, and we would eat in the family room on card tables. The next day, Mom would fix another big dinner (usually turkey (and leftover ham)). This dinner would be the two of us and my grandparents. I loved it, but I know it was a huge amount of work for Mom.
In Steve's family, there was one large Christmas dinner, and it was on Christmas Eve at his grandparents' house (turkey with salt-rising bread stuffing). On Christmas day, his family and his aunt's family would get together at his house for a casual evening together.
Our own traditions have morphed from those two, I think. We have one Christmas meal, and we have it on Christmas Eve at our house. My mom, Steve's dad, our boys, and we gather for a large evening meal (menu varies). Late that night we go to Church for the candle lighting service - it lasts until midnight. The only meal we prepare on Christmas Day is breakfast, and it's easy. Mom comes over, and she and our family share breakfast and enjoy the morning together opening gifts. If I cook any more that day, it is only a pan of brownies to take with us later that day to my brother-in-law's home. The casual evening that Steve and his brother remember is now done at their home with bowls of chili and hotdogs.
Christmas Day is family and relaxing, and might even include a nap.