Eliza Doolittle Day is celebrated annually on May 20, marking the occasion when Eliza Doolittle meets Professor Henry Higgins in the original stage production of "My Fair Lady." This unofficial observance is popular among fans of the musical, which is based on George Bernard Shaw's play "Pygmalion." The day is inspired by the song "Just You Wait" from the film adaptation, where Eliza proclaims the date as her own. The story follows a Cockney flower girl who is transformed into a lady through the teachings of a phonetics expert. Celebrations typically involve appreciation for the musical and its characters, particularly Eliza Doolittle, and may include performances or gatherings among fans.