My friend's birthday

My friend's birthday is February 29th. Only the leap year has 29 days in February, that's why I forgot sending birthday card to my friend this year, but got a present before. I was wondering when I shoud send message with a present on time, then, I wrote " sorry ! I forgot sending birthday wishes on time,'cause this year was different,,,,,,,, Oh what was I about to say? Happy missing birthday!" My friend looks young for his real age and very unique, because he gets age every four years, reasonable? Amazing!