Shavuot Pentecost
In the Bible, Shavuot is called the Festival of Weeks (Exodus 34:22, Deuteronomy 16:10), the Festival of Reaping Ḥag haKatsir (Exodus 23:16), and Day of the First Fruits Yom ha-Bikkurim (Numbers 28:26).
The Mishnah and Talmud refer to Shavuot as Atzeret, a solemn assembly, as it provides closure for the festival activities during and following the holiday of Passover. Since Shavuot occurs 50 days after Passover, Hellenistic Jews gave it the name Pentecost (πεντηκοστή, “fiftieth day”).