The following is an excerpt from this URL.
Everyone agrees that the Messiah kept the right day for the Sabbath during his time on earth. The Jews of that day kept the right day as well because there was never any kind of disagreement on this during that time. So we need only to figure out what day the Jews kept in that time period to determine how to reckon the 7th day Sabbath today. So lets look at the historical record and how the Jews observed the Sabbath in that time period.
“The New Moon is still, and the Sabbath originally was, dependent upon the lunar cycle . . . .” (“Holidays,” Universal Jewish Encyclopedia, p. 410.)
-The Sabbath, as marking the end of the week, reveals its lunar origin; the phases of the moon having taught the shepherds, whose weal or wo depended so largely upon the benevolence or malevolence of the night season, to divide the period elapsing between two new moons into four equal groups (weeks), the last day of each—in imitation of the moon’s coming to rest, as it were—becoming the day of rest. Indications are not wanting that at first the New Moon festival was not counted among the seven days of the week; but after 7✗4 (=28) days had elapsed, one or two days were intercalated as New Moon days, whereupon a new cycle of four weeks began, so that the Sabbath was a movable festival. Later the week and the Sabbath became fixed; and this gradually resulted in taking away from the New Moon festival its popular importance.
– Classification of Festivals
(2) Those connected with the moon: (a) Sabbath;
Probable Lunar Origin.—Critical View:
-The origin of the Sabbath, as well as the true meaning of the name, is uncertain…-It was probably originally connected in some manner with the cult of the moon, as indeed is suggested by the frequent mention of Sabbath and New-Moon festivals in the same sentence…-The Sabbath depending, in Israel’s nomadic period, upon the observation of the phases of the moon, it could not, according to this view, be a fixed day. When the Israelites settled in the land and became farmers, their new life would have made it desirable that the Sabbath should come at regular intervals, and the desired change would have been made all the more easily as they had abandoned the lunar religion.
It’s amazing that these confessions come straight from the Jewish encyclopedia. It specifically says that the Sabbath was originally by the phases of the moon and was not a fixed day like it is today. They try to justify this by saying the Israelites were coming out of a moon cult and that when the Sabbath was turned into a fixed day, that was the proper intent by Elohim. That is an amazing confession. The moon cult spin, is obviously false as Elohim taught the Israelites the true way to calculate the Sabbath using a luni-solar calendar from the beginning of its journey out of Egypt.
Connection with Lunar Phases.
-A division of time comprising seven days, thus explaining the Hebrew name. There are indications of the use of another system of reckoning time, in which the month was divided into three parts of ten days each, the decade being designated in Hebrew by the term ” ‘asor” (Gen. xxiv. 55; comp. the commentaries of Dillmann and Holzinger ad loc.; Ex. xii. 3; Lev. xvi. 29, xxiii. 27, xxv. 9).
This apparently represented one-third of the solar month, while the week of seven days was connected with the lunar month, of which it is, approximately, a fourth.
The quadripartite division of the month was evidently in use among the Hebrews and other ancient peoples; but it is not clear whether it originated among the former. It is unnecessary to assume, however, that it was derived from the Babylonians, for it is equally possible that observations of the four phases of the moon led the Hebrew nomads spontaneously and independently to devise the system of dividing the interval between the successive new moons into four groups of seven days each.
There is ground, on the other hand, for the assumption that both among the Babylonians and among the Hebrews the first day of the first week of the month was always reckoned as coincident with the first day of the month.
The emphasis laid on the requirement (Lev. xxiii. 15) that the weeks of Pentecost (the appointed time of harvest) should be “complete” (“temimot”) suggests that weeks might be reckoned in such a way as to violate this injunction.
This was the case as long as the first day of the first week of the month was made to coincide with the new moon. At the end of four weeks an interval of one or two days might intervene before the new week could begin.
At an early date, however, this intimate connection between the week and the moon must have been dissolved, the chief cause of the fixed week of seven days being, in all probability, the predominance of the seventh day as the Sabbath.
“Declaring the new month by observation of the new moon, and the new year by the arrival of spring, can only be done by the Sanhedrin. In the time of Hillel II [4th century A.D.], . . . the Romans prohibited this practice. Hillel II was therefore forced to institute his fixed calendar . . . .” (“The Jewish Calendar; Changing the Calendar,” http://www.torah.org.)
Maimonides, a Medieval Jewish scholar, and most other Jewish chronologers agree that the modern Jewish calendar is based upon the “mean motions of the sun and moon, the true [calendar] having been set aside.” (Maimonides, Kiddusch Ha-hodesch.)
Philo of Alexandria
In Allegorical Interpretation, 1 IV (8), it says…
“Again, the periodical changes of the moon, take place according to the number seven, that star having the greatest sympathy with the things on earth. And the changes which the moon works in the air, it perfects chiefly in accordance with its own configurations on each seventh day. At all events, all mortal things, as I have said before, drawing their more divine nature from the heaven, are moved in a manner which tends to their preservation in accordance with this number seven. … Accordingly, on the seventh day, Elohim caused to rest from all his works which he had made.” …
Notice that Philo says the moon is perfect in its shape or appearance at seven day intervals. Had a Hebrew speaking Israelite written this he would have said “it perfects chiefly in accordance with its own configurations on each Sabbath day instead of each “seventh” day because elsewhere in his writings, Philo identifies that when he mentions the seventh day [of the week] he is speaking of the Sabbath.
Above, he tells us that the moon perfects its own configurations on each seventh day. It was understood, that at the end each period of six work days there would be a weekly Sabbath. The Greek speaking Jews referred to the Sabbath as the seventh day or the sacred seventh day, while in the language of the Hebrews it was termed Shabbat, or the Sabbath.
The Decalogue XXX (159),
“But to the seventh day of the week he has assigned the greatest festivals, those of the longest duration, at the periods of the equinox both vernal and autumnal in each year; appointing two festivals for these two epochs, each lasting seven days; the one which takes place in the spring being for the perfection of what is being sown, and the one which falls in autumn being a feast of thanksgiving for the bringing home of all the fruits which the trees have produced”…
“And this feast is begun on the fifteenth day of the month, in the middle of the month, on the day on which the moon is full of light, in consequence on the providence of Elohim taking care that there shall be no darkness on that day.”
“…there is one principle of reason by which the moon waxes and wanes in equal intervals, both as it increases and diminishes in illumination; the seven lambs because it receives the perfect shapes in periods of seven days—the half-moon in the first seven day period after its conjunction with the sun, full moon in the second; and when it makes its return again, the first is to half-moon, then it ceases at its conjunction with the sun.” [All emphasis supplied by author/complier of this study.]
The half-moon (first quarter moon) announces the first Sabbath of the month. It is the seventh day of the week, naturally, but this is the 8th day of the month. New moon day is not counted against the week. The full moon rising at the end of the 14th day of the month announces the 15th as the second Sabbath of the month. If the new moon was counted, the quarter phases (or as Philo describes them, the moon as it perfects in its own configurations on each seventh day) would not come at the end of the week, disconnecting the perfection of the lunar cycle from the Sabbath. What Elohim has joined together, let not man put asunder.
“For it is said in the Scripture: On the tenth day of this month let each of them take a sheep according to his house; in order that from the tenth, there may be consecrated to the tenth, that is to Elohim, the sacrifices which have been preserved in the soul, which is illuminated in two portions out of the three, until it is entirely changed in every part, and becomes a heavenly brilliancy like a full moon, at the height of its increase at the end of the second week”.
In other words you have your new moon worship day, then six work days and then the weekly Sabbath on the 8th day of the moon (Ezekiel 46:1). You then have six more workdays and a full moon on day 15 or at the end of the second week or second seven.This proves the new moon was not counted in counting out the weeks same as Yahuwah did not count it in Exodus the 16th chapter when he made the Sabbath known to Moses.
If the new moon was ever counted in counting out the weeks in Scripture, there would be pinpointed weekly Sabbaths on the 7th, 14th, 21st, 28th etc. Yet, you cannot find these days pinpointed as the weekly Sabbath anywhere in Scripture because these days are always preparation days for the weekly Sabbath. When Philo spoke of the 10th or 15th day of the month, he was counting the new moon day in his count, but it is an absolute that when he counted out the week, he did not count the new moon, which in itself proves lunar weeks. Remember Philo is just stating “how” things were done in his day.
“in periods of seven days the moon undergoes its changes. In the first week she becomes half moon; in the second [week], full moon; and in the third [week], in her wane, again half moon; and in the fourth [week] she disappears.”
Clearly these are lunar weeks that are tied to the phases of the moon.
In The Stromata ch.5 says “[Peter] inferred thus:
‘Neither worship as the Jews…[for] if the moon is not visible, they do not hold the Sabbath, which is called the first; nor do they hold the new moon, nor the feast of Unleavened Bread, nor the Feast, nor the Great Day’”
The first is found in the Talmud the Steinsaltz Edition”, Volume XIV Tractate Ta’anit Part II (1995 by Israel Institute for Talmudic Publications and Milta Books), pages 205-206. It says the following regarding the destruction of Solomon’s Temple in Jerusalem by Nebuchadnezzar’s army:
Page 205: “Then late on the day of the ninth, close to nightfall, they set the Temple on fire, and it continued to burn the entire next day, on the tenth.”
Page 206: “When the Temple was destroyed for the first time at the hands of Nebuzaradan [the captain of the guard], that day was the ninth of Av (Abib), and it was the day following Shabbat, and it was the year following the Sabbatical Year…. And similarly when the Temple was destroyed a second time at the hands of Titus, the destruction occurred on the very same day, on the ninth of Av (Abib).”
The historian Josephus records Sabbaths that can be pinpointed and they are on the 8th, 15th, 22nd, and 29th and the New moon was not counted as one of the six workdays. Josephus records an interesting type of strategy by General Pompey and the Romans. The Roman’s saw that the Hebrews did not fight on the Sabbath unless attacked. So, the Romans simply moved their engines and battering rams up to the walls on the Sabbath day, which otherwise they could not do, and on the next day, they battered the city. See page 369-370. Antiquities of the Jews Book 14, Chapter 4, section 3.
“…For although the city [Jerusalem] was taken on the third month, on the day of the fast…” (c) Antiquities of the Jews Book 14, Chapter 4, section 3, p. 370
Footnote c: Antiquities of the Jews Book 14, Chapter 4:3, page 370: “That is on the twenty-third of Sivan, the annual fast for the defection and idolatry of Jeroboam, ‘who made my people Israel to sin,’or possibly some other fast might fall into that month, before and in the days of Josephus.”