CLEAN MONDAY - Also known as Pure Monday, or (in Cyprus only) Green Monday, is the first day of the Orthodox Christian Great Lent. It is a movable feast that occurs at the beginning of the 7th week before Pascha.
The common term for this day, "Clean Monday", refers to the leaving behind of sinful attitudes and non-fasting foods.
Liturgically, Clean Monday - and thus Great 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. In this way, the faithful begin Great Lent with a clean conscience, with forgiveness, and with renewed Christian love. The entire first week of Great Lent is often referred to as "Clean Week," and it is customary to go to Confession during this week, and to clean the house thoroughly (or to have it clean before the beginning of the Fast).