Whitsunday is a Christian holiday celebrated on the seventh Sunday after Easter. It is also known as Pentecost, which is derived from the Greek word for 'fiftieth day'. Whitsunday is traditionally celebrated with special services and activities, such as bonfires, processions, and feasts. The holiday marks the descent of the Holy Spirit upon the Apostles and the beginning of the Christian Church. It is also known as Whit Sunday or Whit Monday in some countries.