Targum Pseudo-Jonathan on Exodus (Exodus 23:16) names two festivals without naming them by their later names: the feast of the harvest first-fruits of the work thou didst sow in the field; and the feast of gathering, at the end of the year, when thou hast gathered in thy work from the field.
These are Shavuot and Sukkot in their earliest form — defined not yet by Torah-giving or by wilderness booths, but by the rhythm of the agricultural year.
The Early Harvest and the Late Harvest
Shavuot comes in late spring, when the first wheat is cut. The barley ripened for Pesach; the wheat ripens seven weeks later. The Torah calls this the feast of the harvest first-fruits — the moment when the opening crops of the new year are brought up to Jerusalem in baskets.
Sukkot comes in autumn, at the end of the year, when everything has been collected — grain, grapes, olives, figs. This is the great pilgrimage of plenty, the moment when Israel stands in front of God with the fullness of the harvest and says: all of this came from Your hand.
Why the Torah Sets the Calendar by Crops
Later tradition layered new meanings onto these feasts. Shavuot became the anniversary of the giving of Torah. Sukkot became the commemoration of the wilderness booths. But the Torah itself starts from the dirt — from the cycle of sowing and gathering that shapes every farmer's year.
Holiness, in the Torah's imagination, is not separate from the field. It rises from it.
The Takeaway
The Jewish calendar was first a harvest calendar. Before revelation and theology and midrash, there was a people walking up a hill with baskets of fruit, thanking the Giver of the rain.