unbirthday 

Statistics prove that you have one birthday, just one birthday every year. But there are three hundred and sixty-four unbirthdays. And this is a reason to gather and cheer.

unbirthday by enken January 10, 2003

unbirthday 

all the days besides your birthday in a year, referred to in Alice in Wonderland also

HAPPY UNBIRTHDAY TO YOU!!!

unbirthday by saxaphoner September 20, 2009

unbirthday 

the day of a sibling's birthday where you also receive presents/money in order to keep the peace.

Jamie: Did your brother have a nice birthday?
Alexandra: He enjoyed it, I also enjoyed my unbirthday.
Jamie: How much did you get?
Alexandra: £230 and an iPad.
Jamie: Tidy.

unbirthday by shr3k May 7, 2011

unbirthday 

When you acknowledge that it is, indeed, the date of your birth, but refuse to acknowledge that you have aged.

Even though it happens to be my eighteenth birthday today, I've decided not to become an adult.

unbirthday by westindiangirl December 17, 2009

Unbirthday 

the opposite of your birthday; the day of your future death

Without knowing, every year we pass our unbirthday.

Unbirthday by sphinxy April 23, 2016

Unbirthday 

Any day that isn't technically your date of birth.
Refers to Louis Carroll's Alice in Wonderland, where there Mad Hatter and his crew celebrate such a day.
Can also be utilized for no damn reason except to celebrate..

Today is my Unbirthday, three and one.

Unbirthday by REBel Siren January 2, 2023

Unbirthday beatings 

Unbirthday beatings are equal to 100 minus your actual age.

These can be given out on any day that is not your birthday, but only once per month per person.

xanthina gives you unbirthday beatings

Unbirthday beatings by xanthina July 4, 2009