Clean Monday, also known as Pure Monday, Ash Monday, Monday of Lent or Green Monday, is the first day of the Eastern Orthodox Christian, Saint Thomas Christians of India and Eastern Catholic Great Lent. It is a movable feast that occurs at the beginning of the 7th week before Orthodox Easter Sunday.
The common term for this day, "Clean Monday", refers to the leaving behind of sinful attitudes and non-fasting foods. It is sometimes called "Ash Monday," by analogy with Ash Wednesday (the day when the Western Churches begin Lent). Liturgically, Clean Monday-and thus Lent itself-begins on the preceding (Sunday) night, at a special service called Forgiveness Vespers, which culminates with the Ceremony of Mutual Forgiveness, at which all present will bow down before one another and ask forgiveness.
Clean Monday is a public holiday in Greece and Cyprus, where it is celebrated with outdoor excursions, the consumption of shellfish and other fasting food, a special kind of azyme bread, baked only on that day, named "lagana" and the widespread custom of flying kites. Traditionally, it is considered to mark the beginning of the spring season. People on Clean Monday usually take their picnic baskets and put inside fasting foods because it is the day that Lent begins.