ALL FOOLS' DAY. The first day of April, known as All Fools' Day or April Fools' Day, is traditionally marked by the custom of playing jokes (usually on friends) and engaging in frivolous activities. It stands as one of the few spring festivals in Christian Europe unaffected by the date of the celebration of Easter. All Fools' Day should not be confused with the Feast of Fools, the medieval mock-religious festival involving status reversals and parodies of the official church by low-level cathedral functionaries and others (held on or about the Feast of the Circumcision, January 1). April Fools' Day activities, however, are related in spirit to this once-licensed kind of revelry. The actual origins of April Fools' practices and their connection to the first of April are unknown. The day and its traditions appear to reflect some of the festive characteristics of...