Another term for a "golden birthday" which means you turn the same age as the day you were born.
It's Shelly's champagne birthday..she turned 19 on the 19th of May!
Is when the day you were born corresponds with the age you are turning. Can be celebrated with drinking champagne. This is not always feasible or you may not be of drinking age yet.
Turning 19 on the 19th day of any month.
"Your gonna be 19 on the 19th, that's your champagne birthday. We're getting you smashed"