The Baha’i commemorates when the Bab, the herald of the Baha’i Faith, announced in Shiraz, Persia (now Iran), that he was the herald of a new messenger of God.
Shavuot, also known as Feast of Weeks, commemorates the anniversary of the day God gave the Torah and Commandments to the nation of Israel assembled at Mount Sinai. Marks the conclusion of the seven weeks following Pesach. Originally a harvest festival.
Pentecost commemorates the descent of the Holy Spirit upon the disciples of Jesus seven weeks (50 days) after the Resurrection (Easter). It also commemorates the founding of the Christian Church, which begins on this day. .