Two Birthdays in a year

Can it be possible for any one to have two birthdays a year. ok. Don't think too complex. It is possible. I have two. One is my actual birthday which is in January and one is official birthday which is today. :) And I always forget and I get mail from IITK Alumni wishing me then I realize "Oh. Today is my birthday. :)"

There is a long story behind this. In short, my DOB changed twice in my school once for writing some Govt entrance exam in 4th Std and once for writing 10th class exams. I am elder to myself if I compare my official birthday with my actual birthday.