"And you shalt observe the feast of weeks, even of the first-fruits of wheat harvest, and the feast of ingathering at the turn of the year." - Exodus Chapter 34:22. Shavuot occurs on the sixth day of the Hebrew month of Sivan. Shavuot commemorates the giving of the Ten Commandments on Mount Sinai.
It is one of the three Biblical pilgrimage festivals and marks the end of the Counting of the Omer.
Less...