The seven calendars listed below are the ones currently utilized by almost all of the Sabbatarian churches observing the biblical annual holy days and the three annual festivals.
1] Jewish (Hebrew) Calculated Calendar
The Church of God 7th Day has been observing the Last Supper/Passover annually since the 1870s, using this calendar to ascertain the date. A few CoG 7th Day members and independent 7th Day Adventists also celebrate the annual festivals, but not all use this calendar.
New Year’s Day (Rosh Hashanah) is the 1st day of the 7th month (Tishri), which is because Jewish tradition declares that “Adam and Eve were created on that day.” All the annual holy days and festivals are calculated from this day, not from the 1st day of the 1st month.
The 1st day of the 7th month (Tishri) is the day of the Molad Emtzai (conjunction), unless one of the four postponement rules apply. In 2026 no postponement rules apply.
[2] Jewish (Hebrew) Calculated Calendar of the Worldwide Church of God
The Worldwide Church of God referred to the Hebrew Calculated Calendar as “God’s Sacred Calendar”. Even so, its founder, Herbert Armstrong, made some changes to it :
• He believed New Year’s Day to be the 1st day of the 1st month, and did not understand that all the dates in the Jewish Calendar are calculated from the 1st day of the 7th month, and thus unknowingly followed the Jewish method of calculation.
• The Lord’s Supper/Passover must be observed on the evening of the 14th of the 1st month, and not on the 15th like the Jews.
It must not be observed with a supper, as Jesus and his disciples did, nor a seder meal as in Judaism, but instead it should be like the Eucharist, Holy Communion or Mass, a sombre ceremony, eating only a tiny piece of unleavened bread and drinking a sip of wine.
• Instead of observing the Festival of Weeks (which the Jews call “Shavuot”) on the 6th of Sivan, 50 days should be counted from the Sunday within the Festival of Unleavened Bread, that Sunday being day zero of the count, so that Pentecost fell on a Monday. For 40 years Herbert Armstrong contended that Sunday was a pagan day of worship, and no holy day would fall on a Sunday. In 1974, however, the 1st Day of Unleavened Bread fell on Sunday, and he was then persuaded by leading ministers that the Hebrew meant that the 1st Sunday should be day 1 of the count. For the remaining 11 years of his life Pentecost was observed on a Sunday.
[3] Day of the astronomical new moon [19th of March 2026],
nearest to the vernal equinox [20th of March 2026].
[4] Day of the appearance of the crescent new moon [likely 21st of March 2026], nearest to the vernal equinox [20th of March 2026].
[5] Day of the astronomical new moon [17th of April 2026],
following the vernal equinox [20th of March 2026].
[6] Day of the appearance of the crescent new moon [likely 21st of March 2026], following the vernal equinox [20th of March 2026].
[7] Day of the appearance of the crescent new moon in the month that the barley in Israel will be ready for harvesting by the Sunday after Passover (Leviticus 23:10-12). [likely 21st of March 2026]
The date of the crescent new moons is confirmed by sighting the new moon in the area of Jerusalem.The dates for the vernal equinox and new moons are based on Jerusalem times.
In the table below, the 3 annual festivals (Exodus 23:14-16) are printed in bold green, and the 7 annual holy days are in bold red. The red numbers along the top row are the 7 most popular biblical calendars.
|
|
[1] |
[2] |
[3] |
[4][6][7] |
[5] |
|
New Year’s Day |
Sab |
Thu |
Thu |
Sab |
Fri |
|
Seder/Passover/ |
Thu |
Wed |
Wed |
Sun |
Thu |
|
Festival of Passover |
April |
April |
April |
April |
May |
|
1st Day of |
Thu |
Thu |
Thu |
Sab |
Fri |
|
7th Day of |
Wed |
Wed |
Wed |
Fri |
Thu |
|
Festival of Weeks |
Fri |
Sun |
Sun |
Sun |
Sun |
|
Day of Trumpets |
Sab |
Sab |
Fri |
Sun |
Sun |
|
Day of Atonement |
Mon |
Mon |
Sun |
Tue |
Tue |
|
Sukkot – Festival |
Sep.26 |
Sep.26 |
Sep.25 |
Sep.27 |
Oct.25- |
|
1st Day of |
Sab |
Sab |
Fri |
Sun |
Sun |
|
|
Sab |
Sab |
Fri |
Sun |
Sun |
“The history of the Jewish calendar may be divided into three periods :–
the Scriptural, the Talmudic, and the post-Talmudic.
The first rested purely on the observation of the sun and the moon, the second on observation and reckoning, and the third entirely on reckoning.”
(The Jewish Encyclopedia : History of Calendar)
Scriptural Calendar
The Mishnah – a collection of 63 tractates, divided into 6 orders, one of them being the Mo’edim (appointed times), shows that the Scriptural Calendar [7] was observed in Jesus’s time at the Second Temple.
“The calendar of the Mishnah is discussed and debated in detail in both the Palestinian and the Babylonian Talmudim … The fact that no other calendar system is ever referred to in the Talmudim may be regarded as significant. In the absence of evidence to the contrary, it is reasonable to assume that the Mishnaic system was perpetuated well into the Amoraic period (third to fifth centuries).” (Calendar and Community, Sacha Stern, p.181)
The first month of the year was when the barley (the early summer grain crop) would be ready for harvesting by the Sunday after Passover (Leviticus 23:10-12).
If there were doubt as to the time of this harvest, the Sanhedrin would consider secondary signs – the sufficiency of lambs for Passover and signs in nature that winter was ending.
“This month shall be unto you the beginning of months: it shall be the first month of the year to you … In the tenth day of this month they shall take to them every man a lamb.” (Exodus 12:2-3)
For, lo, the winter is past; The rain is over and gone; The flowers appear on the earth; The time of the singing of birds is come, And the voice of the turtle-dove is heard in our land; The fig-tree ripeneth her green figs, And the vines are in blossom; They give forth their fragrance. (Song of Solomon 2:11-13)
How was the 1st day of each month determined?
“The beginning of the months were determined by direct observation of the new moon. Then those beginning of months (Rosh Hodesh) were sanctified and announced by the Sanhedrin, the Supreme Court in Jerusalem, after witnesses testified that they had seen the new crescent and after their testimony had been thoroughly examined, confirmed by calculation and duly accepted.” (Arthur Spier, The Comprehensive Hebrew Calendar, p.1)
Witnesses could come from outside Jerusalem, but travel overnight by foot or donkey limited the distance.
After the destruction of the Temple, how did the Palestinian court notify the scattered Jewish communities in the Diaspora of its decisions on the new year and new moons?
… “the dependence of Diaspora communities on the calendrical decisions of the Palestinian rabbinic court. This assumption is based on contemporary rabbinic sources, but these reflect rabbinic wishful thinking rather than historical reality. All the evidence suggests, in fact, that Diaspora communities took charge of their own calendar, without ever referring to Palestinian calendrical authority. (Sacha Stern, ibid., p.100)
By far the largest Jewish community in the Diaspora was in Babylonia, which remained loyal to the Palestinian court, because the Babylonian rabbis observed the Jewish Oral Law (Talmud), which required the calendar to be declared from Palestine. As Babylon is nearly a thousand miles away from Jerusalem, torches were lit along the route to Babylon when the new moon had been sighted, which was critical for the new moons of the first and seventh months, but this was often unsuccessful.
“At the time of the Second Temple, when the Sanhedrin announced the beginning of the months on the basis of observation, the communities living far from the seat of the court could not be reached in time by its messengers. Those communities, in doubt about the day of the New Moon and the festivals, established the custom of celebrating an additional day for each of the major holidays. Thus they were certain to observe the festivals at the same time as their brethren in Israel, on the days sanctified by the Sanhedrin. Whenever the Torah had prescribed one day of holy convocation and prohibition of work, they celebrated two days – except on Yom Kippur to avoid two successive days of fasting. Its observance … (by tradition) became a generally accepted law” (Arthur Spier, The Comprehensive Hebrew Calendar, p.11)
Talmudic Calendar
There followed a lot of discussion among the rabbis in Babylon, recorded in the Babylonian Talmud, on introducing fixed rules that would limit the Palestinian calendar court as to when the calendar months could start.
This was the beginning of the end for the Scriptural Calendar [7] – although a group known as the Karaites continued to observe it as best they could – and they still do so today, but their numbers are now much reduced.
A rule was agreed during the Talmudic period that the 1st month should begin at the new moon nearest the spring equinox. The biblical justification for doing so was dependent upon interpreting the Hebrew word tequfah in Exodus 34:22 to mean equinox.
A further rule that appears to date from the Amoraic period is that of the equinox. Although the equinox is mentioned already in the Tosefta, it only serves as one of a few criteria involved in the intercalation (see section 4.1.2). The rule that emerges in the Amoraic period is that intercalations can and should be made on the sole basis of the equinox.
The rule of the equinox is attested in a single passage in the Babylonian Talmud (Rosh ha-Shanah 21a) … implies that 15 Nisan, the first day of Unleavened bread, cannot occur before the vernal equinox. In this recension, the term aviv is treated as synonymous with tequfah (equinox). (Sacha Stern, ibid, p.184)
Tequfah (Strong’s H8622): a revolution, i.e. (of the sun) course, (of time) lapse).
This Hebrew word is found in 4 verses:
“You are to observe the Festival of Weeks, the first fruits of the wheat harvest, and the Festival of Tabernacles at the turn of the year.” (Exodus 34:22)
“Turn of the year” here refers to the turn of the season from Summer to Winter. (The seasons of Spring and Autumn are not found in the Bible.)
‘And it happened, at the turn of the year, that the army of Syria came up against him…’ (2 Chronicles 24:23)
Armies generally went on the move when the winter rains had ended.
‘And it happened when the time had come around Hannah conceived and bore a son’ (1 Samuel 1:20)
‘… his going forth from the end of the heavens, and his orbit to their ends (Psalm 19:6)
Those keeping calendars [3] and [4] observe the Passover/Lord’s Supper at the first full moon after the vernal equinox, but [5] and [6] require the new moon to be after the equinox, so they sometimes observe it one month later.
Post-Talmudic Calendar
During this period the Babylonian rabbis took full control of the calendar.
The rule of the equinox was replaced by the ‘Metonic’ 19-year time cycle.
The most egregious error was moving the start of the year from the 1st day of the 1st month to the 1st day of the 7th month, so that all of the annual holy days would now be calculated from the latter time, in blatant contradiction to scripture (Exodus 12:2).
The Sanhedrin website states that sighting the new moon is required by Jewish law. The Jews intend to return to sighting the new moon as soon as the current Sanhedrin achieves official status and thus will have the authority to change the calendar. Until then Jewish tradition requires adherence to the calculated calendar.
“A special court has been established to accept evidence concerning the sighting of the New Moon, as required by Jewish Law. This court is made up of various justices who are assembled to hear evidence as the opportunity permits. The purpose of the court is to increase awareness, develop skills, and resolve halachic issues that arise when determining the Jewish Calendar according to testimony by witnesses. At this point there is no intention to supercede the mathematical calendar currently in use and fix the calendar on the basis of the testimony, such a step should be unacceptable to the public and spiritual leadership. Nevertheless, witnesses appear before the court and are investigated with precision according to what they saw. Sometimes the witnesses may also bring photographic evidence to support their testimony. Evidence is already being collected by the yiresh shomaim volunteers throughout the Land of Israel, with the intention that testimony can be presented before the court in a full legal fashion when the peoples’ hearts are ready for it.”
7th Day Churches of God 