Maybe a bit early, but it just turned to be the 24th here, so it counts for me (and I'll be leaving for my folks rather early, so I wouldn't have time to post it later). And yeah, the 24th, Christmas Eve, is the big day, especially for the children.
Some time in the late afternoon, the family will gather with aunts and uncles and grandpas and grandmas (not sure how other families handle it, if they change locations each year or something - we were the only ones with children nearby, so everyone gathered at our place (and now at my sister's due to my nephews), some maybe after the one time of the year they go to church - which is also one way to get the kids out of the house for a while (not sure how often we did that, I recall also spending time at our grandparents instead). Cause when they come back, they may find the living room (or wherever the tree is) closed off to not scare away whoever may come by to bring the presents.
Which is where it gets a bit confusing again thanks to St. Nick: To have their own gift-bringer instead of the Bishop-Nikolaus, protestants introduced the "Christkind", bringing the presents on Christmas instead of the 6th. Not sure if it was that alone, but the Christkind was popular enough to make its way into catholic regions as well, to the point that it got arguably most popular there. But as already said, Nick struck back in his new form as Weihnachtsmann, also coming on the 24th (guess he's taking an east-west route ;) ). I don't have actual numbers, but I would guess they used to be on fairly equal grounds for a while, but given Santa's media presence, I would imagine that he has the upper hand nowadays.
In my days though, I was still waiting for the Christkind, and boy did I wait. As I get to hear almost every year, while the family was gathering in the kitchen, I used to stand before the locked door, trying to get a glimpse through the keyhole. Not sure what I was expecting to see, I doubt I was thinking of baby Jesus or the goldie-locked angel girl it is usually depicted as. But it was like I could feel its presence, something otherworldly. And that magic only increased when the little bell chimed, signaling its leave and time for the "Bescherung", the door finally opening again to let us enter the room, illuminated by the dim lights of the tree, soft Christmas music playing in the background - while trying not to dart over to the presents now under the tree.
Fortunately, we could usually start unwrapping right away. If you were unlucky though, you may have had to perform before that, by reciting a poem, singing or playing instruments - though I'm not entirely sure how much of that is actually done and how much is just stereotypes, especially in regards to the choice of instrument. You see, recorders are (or at least were) pretty much considered "my first instrument", with many kids starting to play one in elementary school (I didn't, but my sister did for example). Problem is, they don't sound all that great, many kids don't like playing it, many adults don't like listening to it. So, "unhappy kids playing Christmas songs off-key" is a bit of a common joke in movies, ads and whatnot.
It could be that some families are even so mean that they're having dinner first before the presents. And that's another matter where Germans are quite torn. Many will have something fancy for dinner, like a "Christmasgoose" with dumplings and red cabbage. On the other hand though, one of he most popular dinners on Christmas Eve is... potato salad with Bockwurst (similar to a hot dog sausage). I guess it kinda depends on whether you have another big feast with the remaining family on the 25th. Since in our case, most of the family is there, we usually fall between those extremes, in that we usually have something a bit more special than your every day meal. Though not having the same meal for each year, it usually means long discussions on what it will be. XD
Afterwards, it's back to the presents and giving the new toys a few test rounds at least. Though I guess for the children, it's already time for bed not too long after that. That's not too bad though - after all, that means getting up early to play while the parents are still asleep. ;)