Earliest possible day on which Pentecost can fall, while June 13 is the latest; celebrated 50 days after Easter Day. (Christianity)

Pentecost
Pentecost is a Christian holiday that takes place on the 49th day after Easter. It commemorates the descent of the Holy Spirit upon the Apostles of Jesus, Mary, and other followers of the Christ, while they were in Jerusalem celebrating the Feast of Weeks, as described in the Acts of the Apostles. Pentecost marks the "Birthday of the Church".
May 10
May 10 is the 130th day of the year in the Gregorian calendar; 235 days remain until the end of the year.
Easter
Easter, also called Pascha or Resurrection Sunday, is a Christian festival and cultural holiday commemorating the resurrection of Jesus from the dead, described in the New Testament as having occurred on the third day of his burial following his crucifixion by the Romans at Calvary c. 30 AD. It is the culmination of the Passion of Jesus, preceded by Lent, a 40-day period of fasting, prayer, and penance.
Christianity
Christianity is an Abrahamic monotheistic religion, which states that Jesus is the Son of God and rose from the dead after his crucifixion, whose coming as the messiah (Christ) was prophesied in the Old Testament and chronicled in the New Testament. It is the world's largest and most widespread religion with over 2.3 billion followers, comprising around 28.8% of the world population. Its adherents, known as Christians, are estimated to make up a majority of the population in 157 countries and territories.