Also known as Orthodox Shrove Monday or Ash Monday.
Clean Monday begins the season of Great Lent in Eastern Orthodox Churches.
Great Lent corresponds to Lent as found in Western Christianity, though the length of the periods are calculated in different ways. They both use a period of 40 days between the beginning and end of Lent, because of the 40 days that Jesus is said to have spent fasting the desert. However, Western Christendom doesn't count Sundays because Jesus is recorded as having resurrected on a Sunday, whereas Eastern Orthodox churches do count Sundays.
This first day of Great Lent is called "Clean Monday" because Christians should begin the holy season with "clean hearts and good intentions." It is also because the season of Lent is regarded as a time for when Christians should clean up their spiritual house, coming to terms with their lives and rededicating themselves to a more holy and righteous way of living.
Clean Monday is a day of strict fasting. Christians are not allowed to eat from midnight to noon and can have no meat at all. Christians are also expected to spend extra time praying during the day and reading from the Bible.
Because Clean Monday is also considered to mark the first day of spring. Hence Greeks tend to celebrate it with outdoor activities and picnics rather than fasting and prayer.
Traditional foods include olives, octopus, and shrimp. In addition to picnics, outdoor activities used to celebrate the day include flying kites, dancing, music, etc.
