They celebrated the Feast of Harvest seven weeks after Passover. This was about the end of the barley harvest and the start of the wheat harvest (mid-May to mid-June). In later Judaism, this feast marked the giving of the covenant at Mount Sinai. This happened 50 days after the first Passover in Egypt (see Leviticus 23:15–21; Deuteronomy 16:9–12).
They celebrated the Feast of the Ingathering on the fifteenth day of the seventh month of the Hebrew calendar (mid-September to mid-October). This was after the grape harvest ended. This feast remembered the time in the wilderness when God provided for his people.