Happy Birthday! September 9 is the most common day for a birthday.   (ask your parents) 
We didn’t really start celebrating birthdays until… calendars. 

Who has a birthday today?  
Adam Sandler, Michael Bublé and Colonel Sanders to name a few.

Note:  Other sources say the most common birthday day is 9/16.  Whichever day is right…You should celebrate all month anyway. ;0)
So if September is “your” month?  cheers!