Few people notice accurately the chiastic structure found in Bereishit 1:14-19. I will use color to show what that structure is. The structure will reveal what phrases go together.

14 And Elohim said, Let there be lights in the firmament of the heaven
to divide the day from the night; and let them be for signs, and for seasons, and for days, and years:
15 And let them be for lights in the firmament of the heaven to give light upon the earth: and it was so.
16 And Elohim made two great lights;
the greater light to rule the day, and the lesser light to rule the night: he made the stars also.
17 And Elohim set them in the firmament of the heaven to give light upon the earth,
18 And to rule over the day and over the night, and to divide the light from the darkness:
and Elohim saw that it was good.
19 And the evening and the morning were the fourth day.

Notice how the colors go together:
The color red shows that days and years are solar events: spring is like morning, summer daylight, fall evening, and winter night
The color blue shows that 'signs' (Otot) and 'seasons' (moedim, appointed times) are lunar events;
The color green shows that days and nights are divided by two or three stars, according to the law of two or three witnesses.

That is, when two or three witnesses confirm the sighting of two or three stars following sunset, it is the official onset of a new day. This is relevent in sighting the new moon crescents because often when seen in the erev concluding the 30th day of the previous month, the crescent will be seen either before or after the sighting of three stars. If before, the end of day 1 of new month is being witnessed and the previous month was but 29 days. If after three stars, it is the beginning of the first day of the coming month and the previous month had 30 days.

Recall that there is a structure called chiasm in the verses. This is reminiscent of when YHWH confronted Adam and Eve in the Garden after their transgression. Firts He addressed Adam, who promptly blamed Eve; then Eve in turn blamed the serpent. That order is 1, 2, 3, or A, B, C or any other way one cares to label it. Above we chose Green, Blue, Red. When YHWH pronounced judgments, He reversed the order and addressed the serpent, then the woman, then the man. 3, 2, 1, or C, B, A. We see such a pattern above that starts out green, blue, red; then it is reversed to red, blue, green in verses 16 and 18. The brown phrases go together also, but the example is simplified to show the STRUCTURE underlying the text.

The next point is that Yeshua has established for us a most important principle of exegesis, one that he himself uses to get his understanding the Scriptures.

Yochanan 10:34 34 Yeshua answered them, "Is it not written in your Torah, 'I said You are Elohim'? 35 If he called them Elohim to whom the word of Elohim came, and the scripture cannot be broken;

The Scriptures cannot be broken is the prinicple, and along with other principles such as the law of two or three witnesses that is used to determine the truth, these are used to develop a correct understanding of what scripture is teaching us.

This principle is based on the belief that while many men wrote the Scriptures, including the scriptures of haBrit haChadasha, it is none other than haRuach haKodesh (the Holy Spirit) who has authored the entirety of the Scriptures. This is the principle of the divine inspiration of the Scriptures. These principles cannot be violated in the interpretations people are want to give; doing so leads to error, bad doctrine, and false teaching.

Now that we know the Scriptures cannot be broken, let's take a look at

Ps. 104:19 He made the moon for moedim, the sun knows its going down.

This verse confirms the the lesser light of Genesis 1:14, 16, and 18 is the moon, and that it has a role in determining moedim (appointed times).

The question for us now becomes, "Well, what are the appointed times?" Scripture gives us the answer for this in Leviticus, chapter 23.

Vayiqra 23:1 And YHWH spake to Moshe, saying, 2 "Speak to the sons of Israel, and say to them, concerning the moedim of YHWH, which you shall proclaim to be set-apart assemblies, even these are My moedim. 3 Six days shall work be done: but the day of the seven is a Sabbaths of rest, a called out set-apart assembly; you shall do no work therein : it is sabbath unto YHWH in all your sabbathings. 4 These are the moedim of YHWH, even set-apart assemblies, which you shall proclaim in their moedim.

Here we see that Sabbath is referred to as the first in the list of appointed times, of which Genesis tells us are determined by the lesser light, the moon, and which Ps. 104:19 confrims; and the Scriptures cannot be broken. Shabbat is a moed. What about 'signs'? We now turn to the book of Exodus.

Shemot 31:13 Speak you also to the sons of Israel, saying, "Awmein My sabbaths shall you observe: for it is a sign between Me and you throughout your generations; that you may know that I am YHWH who does sanctify you." 14 You shall observe Sabbath therefore; for it is holy to you: every one that defiles it shall surely be put to death: for whosoever does any work therein, that soul shall be cut off from among his people. 15 Six days may work be done; but in the seventh is a sabbath of rest, holy to YHWH: whosoever does any work in day of the sabbath, he shall surely be put to death. 16 Wherefore the sons of Israel shall keep sabbath, to observe sabbath throughout their generations, for a perpetual covenant 17 It is a sign between me and the sons of Israel forever: for in six days YHWH made heaven and earth, and on the day of the seven he rested, and was refreshed."

Here in this very literal translation it is seen that not only is Sabbath an appointed time (moed) but it is also a sign (Ot). Signs and Appointed times are rule by the moon as we have previously seen. Shabbat is both an OT and a MOED according to the Scriptures that cannot be broken. One thing is certain, is that the Sabbath of tradition is not ruled by the moon.

Without saying how to count, this apologetic response provides with the necessity of counting according to the Scriptures and it is clear, the traditional timekeeping has made the commandment of YHWH of none effect.

Matthew 15:5 But you say, Whosoever shall say to his father or his mother, It is a gift, by whatsoever you mightest be profited by me; 6 And honor not his father or his mother, he shall be free. Thus you have made the commandment of Elohim of none effect by your tradition

And the Scriptures cannot be broken.