Genesis 1:14

14 And God saith, `Let luminaries be in the expanse of the heavens, to make a separation between the day and the night, then they have been for signs, and for seasons, and for days and years,

Genesis 1:14 Meaning and Commentary

Genesis 1:14

And God said, let there be lights in the firmament of
the heaven
In the upper part of it, commonly called the starry heaven: some writers, both Jewish and Christian, and even modern astronomers, understand this only of the appearance of them, and not of the formation of them; they suppose they were made on the first day, but did not appear or shine out so clearly and visibly as now on the fourth day: but it seems rather, that the body of fire and light produced on the first day was now distributed and formed into several luminous bodies of sun, moon, and stars, for these were (tram) , "from light"; lights produced from that light, or made out of it; or were instruments of communicating and letting down that light upon the earth F8, which was collected and put together in them, especially in the sun: and the uses of them were to divide the day from the night;
which is the peculiar use of the sun, which by its appearance and continuance makes the day, and by withdrawing itself, or not appearing for a certain time, makes the night; as the light by its circular motion did for the first three days, or the diurnal motion of the earth on its axis, then and now: and let them be for signs, and for seasons, and for days and
years;
for "signs" of good and bad weather; for the times of ploughing, sowing, reaping and for the "seasons" of summer and winter, spring and autumn; for "days" by a circular motion for the space of twenty four hours; and for "years" by annual motion for the space of three hundred sixty five days and odd hours. The Targum of Jonathan is,

``and let them be for signs and the times of the feasts, and to reckon with them the number of days, and, sanctify the beginnings of the months, and the beginnings of the years, and the intercalations of months and years, the revolutions of the sun, and the new moons, and cycles.''
And so Jarchi interprets "seasons" of the solemn festivals, that would hereafter be commanded the children of Israel; but those uses were not for a certain people, and for a certain time, but for all mankind, as long as the world should stand.
FOOTNOTES:

F8 (rwa) "significat lucem illam primam per sese lucentem"; (rwam) "vero corpus per quod lux illa prima splendorem suum demittit". Nachmanides, apud Fagium in loc.

Genesis 1:14 In-Context

12 And the earth bringeth forth tender grass, herb sowing seed after its kind, and tree making fruit (whose seed [is] in itself) after its kind; and God seeth that [it is] good;
13 and there is an evening, and there is a morning -- day third.
14 And God saith, `Let luminaries be in the expanse of the heavens, to make a separation between the day and the night, then they have been for signs, and for seasons, and for days and years,
15 and they have been for luminaries in the expanse of the heavens to give light upon the earth:' and it is so.
16 And God maketh the two great luminaries, the great luminary for the rule of the day, and the small luminary -- and the stars -- for the rule of the night;
Young's Literal Translation is in the public domain.