An unbirtday is any day of the year which is NOT your birthday. This wonderful concept was introduced in Alice's Adventures in Wonderland. Alice's Adventures in Wonderland is an 1865 novel written by English mathematician Charles Lutwidge Dodgson under the pseudonym Lewis Carroll. Alice attends an unbirthday party in that novel. It occurred to me the first time I read it that anybody could have 364 unbirthday parties a year instead of just one birthday party.
Yep ( actually only the tea party was in the first book, the concept of an unbirthday was introduced in Alice through the looking glass )
How do you celebrate your unbirthday