The Ordinances of the Sun and the Moon

Genesis 1:14 And YHWH 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.

The Sun, Moon & the stars or as scripture would refer them as Host of Heaven, As their many scriptural references of the Israelite of having to build high alters to worship the host of heaven, as being it was a spoken command by YHWH unto Israel, to refrain from worshiping them (Deuteronomy 4:19). Scripture also records that the Sun & Moon were observed by the Israelites for signs, seasons and to discern days of the months, throughout the entire year, figuratively New moon   
                                                                                                                 being acknowledged as the Sign of a New month.

The Gregorian calendar on the other hand, which is a reformed calendar of the Julian calendar where are both instituted by the Roman Empire, are calendars governed only by the Sun. Among the fact that the Gregorian Months & Days are dedicated to pagan Gods, as the entire Gregorian calendar is constituted by a winter / Summer solstice and a spring / autumn equinox.

Scriptural references regarding the ordinances of the Sun and Moon

Question: What is a Solstice?

Answer: Solstices occur when the sun is at its greatest distance from the equator. Solstice is derived from two Latin words: "sol" meaning sun, and "sistere" to cause to stand still. The perception that the "sun stands still" comes from the shadow on the sun dial changing minimally on and near the solstices. Solstices only occur twice a year, which is a winter solstice and a summer solstice. The Winter Solstice, also called 'Yule', marks the first day of the season of winter. It falls on or near 21 December. The Summer solstice is the time when the sun reaches its northern most latitude and therefore appears at its highest in the sky at noon. At this time of year we have the longest day.

Question: What is an Equinox?

Answer: Equinoxes occur when the axis of rotation of the earth (i.e. the line form the N to S poles) is exactly parallel to the direction of motion of the earth around the sun. This happens on just two days of the year, the spring and autumn equinoxes. This means that day length is exactly the same (12 hours) at all points on the earth's surface on these days (except right at each pole, where it will be about to change from permanent light to dark, or vice versa). The name equinox is derived from the Latin aequus (equal) and nox (night), because at the equinox the night and day are nearly equally long. Equinoxes only occur twice a year, which is a spring equinox and a autumn equinox. The Autumn Equinox is the first day of the autumn season and occurs when the sun passes the equator moving from the northern to the southern hemisphere. The North Pole begins to tilt away from the sun. Day and night have approximately the same length. The Autumnal equinox is near 22 September. The Spring Equinox is the first day of spring season and occurs when the sun passes the equator moving from the southern to the northern hemisphere. The North Pole begins to lean toward the sun again. Day and night have approximately the same length. The Spring Equinox is near 20 March.

Question: Is the Hebraic calendar constituted by a solstice and an equinox?

Answer: No. The Hebraic calendar is constituted by the lunar phases of the moon, as in the days of the months throughout the year is governed by a New moon as a signal of a New month. In Ancient Israel, the Sun was acknowledged only to govern the hours within the day.

Upon comparing the Hebraic lunar calendar and the Gregorian calendar, only one calendar is governed by the New moon which is the calendar mentioned throughout many scriptures.

Day and Night
In part of the ordinances of the sun & moon, these two celestial lights were created to divide the night (dark) from the day (light) as per Genesis 1:14.

Many today are under the perception that a day starts at dusk as in evening to evening would be a complete cycle of one day. The Scriptures however, do portray another version of what is really a day which can viewed in this link called,
Day & night questions.

Light by Day - The Sundial
Jeremiah 31:35
Thus saith the Lord, which giveth the sun for a light by day, and the ordinances of the moon and of the stars for a light by night, which divideth the sea when the waves thereof roar; The Lord of hosts is his name

A sundial is a device indicating the time during the hours of sunlight by means of a stationary arm (the gnomon) that casts a shadow onto a plate or surface marked with lines indicating the hours of the day. Sundials were commonly used in ancient civilizations including ancient Israel. Sundials endured as the most accurate form of time-keeping, even after the invention of clocks.

: What is a gnomon ?

Answer: The gnomon is the part of a sundial which casts the shadow. It is the pointer (stick) on a
               sundial, which by its shadow, shows the hour of the day.

The Shadow on the Sundial
King Hezekiah was one of the Kings of Judah as faithfully led the nation of Israel in very difficult times. Hezekiah did however become sick and was near death. YHWH sent the prophet Isaiah to Hezekiah with a message, “Set your house in order, for you shall die and not live” (Isaiah 38:1 &
2 Kings 20:1
). Hezekiah fervently prayed unto YHWH, and his prayer was heard, and YHWH promised to add 15 years to his life. As a sign to confirm this promise, YHWH said, “Behold, I will bring the shadow on the sundial, which has gone down with the sun on the sundial of Ahaz, ten degrees backward” (Isaiah 38:7-8 & 2 Kings 20:9-11)

Some translations render the Hebrew term maalah for degrees as “stairway” (see NAS, CSB). The NET Bible notes, “These steps probably functioned as a type of sundial.”

Whether the term means “steps” or “sundial,” certainly what is under consideration is a means of telling time by the moving shadow cast by the sun. The miraculous sign was that the shadow would return, it would go backward by 10 “steps” or “degrees.”

Herodian Temple Sundial

This tiny stone sundial (only 2 inches wide by 2 inches high) may be the only known surviving artifact from the Temple of King Herod. It was found during excavation of a pile of debris attributed to the destruction of the Temple, destroyed in A.D. 70. Notice the seven-branched menorah carved on the back, which is a symbol that was usually reserved for the Temple Priests. Perhaps it was used by the temple priests to ascertain their time of service at the Temple.
Ancient sundial with Aramaic inscription displayed in the Archeological Museum in Istanbul.
Food For Thought

The question that I do ask to those who keep a Saturday sabbath or a secular 7th day sabbath without the lunar cycle, is of how would you know on what day the month you're in, if your stranded on a deserted island? In consideration that you have no access to a Gregorian calendar. Personally, all I have to do is look up at the moon at night to determine the numbered day of the present month.  As per instructed in Eccl. 43:6 (Apocrypha), Jeremiah 31:35 & Genesis 1:14 which does gives clear indication, that the lights of the heavens are my methods of telling time. The Moon is for the days of the month and the Sun is for the  hours within a day.