December, in general, tends to be a busy month, it is also an expensive month, and this means it is not an ideal month for birthdays. In particular, ones that happen during the week or so around Christmas*.
There is this strange occurrence that happens when your birthday falls around Christmas with regards to gifts. People either give joint gifts (“Happy Birthday/Christmas!”) or go out of their way to ensure you have birthday and Christmas gifts (very thoughtful). Since everyone is so busy during this time though you also often get belated gifts.
I enjoy the belated gifts. Not because it extends my birthday beyond just the day, I don’t need a week of being spoiled. No, I enjoy belated gifts because sometimes those gifts arrive when other things in your life are just really messy and they are a little bright spot in the darkness.
Plus sometimes the gifts come with cake. 🙂

*Assuming you celebrate Christmas, though I am sure the same is true for anyone who has a birthday near a holiday they celebrate.