In Austria the main thing is the evening of 24th December.
In families with little children one of the parents leaves home with them in the early afternoon to give time to the other parent to decorate the tree. Decorations are various here. Some still use apples, nuts stars made of straw, little wood-carvings and cookies. Many of the things are home-made. Others use glass-balls and beads - often also hand-decorated or hand-made..
On every tree there are different bells
Parcels with gifts are put under the tree.
In the early evening a nice dinner is served, usually some kind of fish. Only closest family is taking part traditionally. Grand-parents may invite their children with their families, but most times it´s just parents and children, maybe grand-parents and one or other uncle or aunt without own family.
After dinner someone surrepititiously enlightens the candes on the tree, rings a bell and children are allowed to enter the room where the tree stands.
Some carols are sung and then everyone gets his presents.
Afterwards family stays together by the candle-light, playing with the children, talking, eating some Christmas-Cookies.
Many people also have a creeche under the tree. And many people who never go to church, go to the great midnight-masses played by good orchestras in many churches.