We met Baby Spouse at 3 days old and he was placed at 17. It seems a bit pointless to have a big celebration for either of those as they are so close to his birthday, and when he's older he'll definitely want to celebrate his birthday. He was cleverly born on my mother's birthday, rather than his due date which is my brother's birthday, so at least some of the family will remember it (though my brother has a 100% failure rate so far, but we didn't make a big deal of his first birthday, so are less bothered than we could be).
We didn't find out his adoption was finalised until a few days after, so just said a private "yay" and told people as it came up. I actually just had to ask Mr Spouse when it was, and it's in a week or so, but I doubt it will be a day we celebrate a lot either, though maybe we'll raise a glass.
So birthdays it is. Last year we arrived in the US the day before, but kept to ourselves for a few days, and saw birth family a few days later. We are thinking of an adult and child, combination New Year buffet and birthday party next year, it's a good time of year for family and adult parties. It may not be so excellent for school age parties, but we'll cross that bridge when we come to it. Maybe ice skating the weekend they go back to school. My mother complains that she always got combined birthday and Christmas presents as a child so we will watch for that. We don't want to raise a materialistic child but some of these things hit a small child hard.
But we don't think we'll be going back to see birth family in January again. We're more likely to see other family and to be able to travel more (my cousin's little girl is 3 days older and lives in New England) at other times of year. I am not sure if this will be a relief or disappointment to birth family. We haven't told the grandparents yet, and we were due to have a phone call with Nella but they don't have a current cell phone number for her (as of a month ago) so we suspect she's gone off grid again. We are fairly confident she'll turn up again, and in our heads we know we might go to visit her and have her not turn up, but I guess we weren't expecting it so soon, especially given that we talked regularly last year.