Pentecost is a period of time in the Christian faith where Christians celebrate the period of time that took place after Easter. It is celebrated because it represents the time after the crucifixion and resurrection of Jesus. This time is 7 weeks or about forty-nine or fifty days. Figuring out Easter is a little difficult because it does not fall on the same date every year like Christmas. Easter occurs always on a Sunday.
It is determined by the full moon or ecclesiastical moon. It is the first full moon that takes place on or after March 21st. Then that is Easter. To determine Pentecost, it would be the seven weeks after Easter Sunday. People usually wear and decorate the church in red and white.