Shavuot (listen (help·info)), or Shavuos (listen (help·info)) in some Ashkenazi usage (Hebrew: שָׁבוּעוֹת, Šāḇūʿōṯ, lit. “Weeks”), commonly known in English as the Feast of Weeks, is a Jewish holiday that occurs on the sixth day of the Hebrew month of Sivan (in the 21st cenutury, it may fall between May 15 and June 14 on the Gregorian calendar). In the Bible, Shavuot marked the wheat harvest in the Land of Israel (Exodus 34:22). In addition, Orthodox rabbinic traditions teach that the date also marks the revelation of the Torah to Moses and the Israelites at Mount Sinai, which, according to the tradition of Orthodox Judaism, occurred at this date in 1314 BCE. – Wikipedia