My birthday is in late November.
Yesterday, Dec. 15, I got a card from my 20 y.o. German grandson.
Presuming it to be a Christmas card, I opened it to read, Herzlichen Glückwunsch zum Geburtstsag, (heartfelt congratulations for your birthday).
I emailed his dad, (my eldest son), to say, "Gotta love your kid, I got a birthday card from him today, 3 weeks late!"
He replied, "He sent it in mid November, it's Deutsche Post's way of debunking the myth of German efficiency."