Pentecost (πεντηκοστή [], pentekostē [hēmera], "the fiftieth day") is one of the prominent feasts in the Christian liturgical year, celebrated the 49th day (7 weeks) after Easter Sunday—or the 50th day, inclusively, whence its name is derived from the Greek. Pentecost falls on the tenth day after Ascension Thursday. Historically and symbolically related to the Jewish harvest festival of Shavuot or the day, fifty days after the Exodus, on which God gave the Ten Commandments at Mount Sinai. In the New Testment times, Pentecost now commemorates the descent of the Holy Spirit upon the Apostles and other followers of Jesus as described in the Book of Acts, Chapter . Pentecost is also called Whitsun, Whitsunday, or Whit Sunday, especially in the United Kingdom. (via Wikipedia)