A rare metal,  stadium lights and the year you were born.  
Dysprosium, a rare metal, is used in the bulbs to light up a stadium; it has an atomic weight of 66 and was isolated in 1953.  Connie Mack Stadium in Philly got its name that same year, 1953 is also the last year the Phillies and the “A’s” both called that stadium home.
(The A’s moved to Kansas City.)  
Your birthday?  Let’s use those numbers:
Subtract your age from the number 66.  
Then add 1953.
You’ll get the year you were born.…Enjoy your day.