Holidays are celebrated for a variety of reasons, including commemoration of historical events, as well as particular days that have ethnic, cultural and religious significance. The celebration of particular holidays is unique to each culture and society.
Some holidays, such as Christmas, New Year's, Thanksgiving and Halloween, are festive events that involve celebrations among family and friends. Other holidays serve as serious reflections of past events. One such holiday is Memorial Day, which recognizes the contributions of military service.
Many people in modern society, however, question the celebration of particular holidays. Christmas, for example, is often decried for its commercialized aspects.