Then God said, “Let there be lights in the expanse of the heavens to separate the day from the night, and let them be for signs and for seasons and for days and years; and let them be for lights in the expanse of the heavens to give light on the earth”; and it was so. God made the two great lights, the greater light to govern the day, and the lesser light to govern the night; He made the stars also. God placed them in the expanse of the heavens to give light on the earth, and to govern the day and the night, and to separate the light from the darkness; and God saw that it was good. There was evening and there was morning, a fourth day. Genesis 1:14-19 NASB
On the fourth day of creation, God spoke into existence the sun, the moon, the stars and the planets (lights in the expanse of the heavens) and declared their function for man upon the earth. He defined these lights and the dimension of the influence each would have upon the earth.
The sun and the moon, the most important lights, were created by God and placed to give the primary light unto the earth. The sun would give the greater light of day; the moon would rule over the night and reflect the light of the sun. Their purpose was to separate light from darkness. They were established to not only give light during the day and night, but were also to give signs unto man and to mark seasons, days and years.
Man can only look to the heavens for the signs of the seasons. Man can observe, record, and calculate (today it is with great accuracy) when and where on the earth that the sun and moon will divide light from darkness. Using this we can determine the days, years, and the dark new moons that establish the seasons of the Lord, including the Jewish feasts.
The dates of equal day and night equinox in Jerusalem occur in March (16th or 17th) and September (26th or 27th). The first dark new moon date of the equal night and day equinox in March appoints Passover to occur on or after the date of the equal day and night equinox. The Feast of Tabernacles occurs at the end of the year’s major food harvests of the agricultural cycle of what was sown in the field in Israel.
Both day and night belong to You; You made the moon and the sun. You set the boundaries of the earth, and You made both summer and winter. Psalm 74:16-17
He made the moon for the seasons; the sun knows the place of its setting. Man goes forth to his work and to his labor until evening. Psalm 104:19 & 23 NASB
“And God saw that it was good.” He set these lights in place for us!