This is what I learned today reading Het Parool, the Amsterdam newspaper.
The date for Easter every year is the first Sunday after the first full moon in spring. Who said so? The Council of Nicea back in 325.
This year, the first full moon of spring is on Friday, March 21. That is why Easter is this Sunday, March 23. The last time Easter came this early was in 1913 and the next time will be in 2228.
The Ascension of Jesus (celebrated in many countries as a holiday, and known in the German-speaking countries as Himmelfahrt and in the Netherlands as Hemelvaart) is always 40 days after Easter. So this year it falls on May 1 which deprives several countries of an extra holiday (May 1, Labor Day).
Pentecost is 50 days after Easter, so this year it is on May 11. Pentecost is the celebration of the descent of the Holy Ghost on the Apostles, which takes place, naturally 50 days after the resurrection of Christ.
