Pentecost is significant in both the Old and New Testaments. Pentecost is a Greek festival known in the Old Testament as the Feast of Weeks. The Greek word means fifty refers to the fifty days that have elapsed since the wave offering of Passover. A wave offering of Passover—signals the offering that is waved before God at the altar will not be burned, and shows that the offering being waved belongs to God.
The Feast of Weeks celebrated the end of the barley, then wheat grain harvest. Pentecost in antiquity signaled the start of the church age. Pentecost is May 28th in the Christian church.
Shavuot is a two-day Jewish holiday that falls on the Hebrew calendar dates of Sivan 6–7. Shavuot 2023 begins at sundown on Thursday, May 25, 2023, and concludes at nightfall on Shabbat, May 27, 2023. Then the 10 Commandments are read on May 26, 2023.