I am extremely sorry for the belated birthday greeting! I do not know how to apologise for this overlook.
I know that your birthday is on the 25th of December, but unfortunately, I was on a trip at the Danube for Christmas, and I mixed up the days. As we stayed there a whole week, with minimum internet service and simply relaxing and hanging out, I honestly forgot what day it was.
It was not until I came back on the 27th that I realised that I had missed your birthday ...