And the Lord said, Let there be lights in the expanse of the heavens, to distinguish between the day and the night; and let them be for signs and for festival times, and for the numbering by them the account of days, and for the sanctifying of the beginning of months, and the beginning of years, the passing away of months, and the passing away of years, the revolutions of the sun, the birth of the moon, and the revolvings (of seasons).
The Lights of Heaven Were Made for the Jewish Calendar
Targum Pseudo-Jonathan on Genesis 1:14