Old Maid's Day is observed on June 04, 2018. Old Maid's Day brings awareness to those of us who have not yet found their Prince Charming. An old maid, or spinster, is an older, childless woman who has never been married.
A "spinster" is not simply a "single" woman, but a woman who has not formed a human pair bond by the time she is approaching or has reached menopause and the end of her reproductive lifespan.
Old Maid's Day has it's origin in the ending of World War II. Many GIs did not return home, why dances and socials were held to bring together returning soldiers and the available, unmarried ladies. (With material from: Wikipedia)