Still waiting on that proposal? Today you can propose to him!
This tradition supposedly began in Ireland in the 5th century when St. Bridget complained to St. Patrick that the sisters in her nunnery were unhappy that they weren’t able to propose to men, and apparently the men weren't beating down the nunnery door to propose to them. (Did you think that nuns weren’t allowed to marry? Me too! It seems things were very different then.) In response, St. Patrick agreed to allow one day every four years--Leap Day--when women could propose.
Is the story true? Who knows. Some feel that it's doubtful, but still the legend persist.