The Sacred Calendar: Easy as 1-2-3

Updated August 23, 2025

The purpose of this short article is to show that, according to God’s holy, written Word in the Bible, the sacred calendar calculations are quite simple!

We do not need to adopt the Jews’ obviously-erroneous, super-complicated, post-biblical, unscriptural calculation methods … methods which are only partially detailed in the web-site at: https://en.wikipedia.org/wiki/Hebrew_calendar

In fact, the calendar calculation methods given to us in the holy scriptures by the LORD God are “as easy as 1-2-3” in which:

Not that we’re to worship the sun or the moon, of course ... only that the Lord Jesus and His Father have given the sun and the moon to us “to divide the day from the night and for signs and for seasons, and for days, and years.” (Genesis 1:14).

1-2-3 Instructions for the timing

Starting with the timing of the first month of the sacred year – i.e. God’s true New Year’s Day:

  1. FIRST, we look up the date and time of the Vernal (Spring) Equinox … at Jerusalem.
  2. SECOND, we look up the date and time of the next Lunar Conjunction (New Moon) at Jerusalem, following the Vernal Equinox.
  3. THIRD, we look up the next sunset (at Jerusalem) following that Lunar Conjunction. 

That sunset is the beginning of the first day of the first month of the true New Year.

We can then apply rules 2 and 3 to all eleven subsequent months – i.e. months 2 to 12.

Occasional Thirteenth Months

As the twelfth month draws near, we look for the next cycle, beginning with the next Vernal Equinox.

Because of the difference between the lengths of the “Lunar Year” and “The Solar Year,” it will occasionally be necessary for a thirteenth month to be added.  These occasional thirteenth months are called “intercalary” months. 

We don’t need to artificially add or to pre-calculate these intercalary years. They fall into place naturally and automatically -- depending on the timing of the Vernal Equinox and the above three rules.

Explanation of 1-2-3 Terms

• The Vernal Equinox is the instant at which the Earth's Equator passes the centre of the Sun, so initiating the Springtime of the year in the northern hemisphere.

The date and time of each Vernal Equinox can easily be determined today. Accurate tables can be found on the Internet: 
e.g. https://www.timeanddate.com

Although Adam, Noah, Abraham, Moses and perhaps other brilliant servants of the Eternal God did not have the same tools that we have at our fingertips, we can be sure that they did have methods for its annual calculation, as revealed to them by Him.

Historians and anthropologists tell us that many ancient societies knew exactly when the Equinoxes fell each year – initially by frequent, regular observation – later by mathematical calculation.

The instant of the Vernal Equinox can occur at any time of day or night.

Astronomically and scientifically, the three-month period prior to the Vernal Equinox is winter-time; and the three-month period after the Vernal Equinox is spring-time.  Therefore, God’s true New Year cannot begin until after the Vernal Equinox.

• A Lunar Conjunction (a.k.a. “New Moon” or “Dark Moon”) is the instant when the earth, moon and sun (in that order) are in a basically straight line. (Occasionally, when they are in a more perfectly straight line, a lunar eclipse will occur at the time of the Conjunction).

The date and time of each monthly Lunar Conjunction can easily be determined today.  Accurate tables can be found on the Internet.

For reasons that should be obvious, visual sighting of the actual Conjunction with the naked eye is impractical, inaccurate, or impossible for most people, and is unnecessary.

Just as with the Vernal Equinox: Adam, Noah, Abraham, Moses and perhaps other brilliant servants of the LORD God likely had the Lunar Conjunction and methods for its subsequent annual calculation revealed to them by Him.

Also, as with the Vernal Equinox, we know -- from history and archaeology -- that many ancient societies had the ability to accurately determine the Lunar Conjunctions – initially by frequent, regular observation – later by mathematical calculation. 

The Lunar Conjunction can occur at any time of day or night.  Therefore actual the day on which the Lunar Conjunction occurs cannot be used as the New Moon Day for God’s calendar – because any hours and minutes of the Lunar Conjunction day prior to the conjunction itself would be “Old Moon” hours and minutes.  So, a full, complete, 24-hour New Moon Day must begin at the sunset following the time of the Conjunction.

• Sunset (or Sundown) is the daily disappearance of the sun below the western horizon, as a result of the Earth's rotation.

The time of each daily sunset can easily be determined today. Accurate tables can be found on the Internet.

Sighting is both unnecessary and, in most locations, imprecise. 

Most true Christians and Jews today do not attempt to sight the sunset for the determination of the starting and ending times of their weekly Sabbaths – but depend on more reliable astronomical tables.

Why from Jerusalem?

Why do we determine and fix these days and times from Jerusalem? 

Because, to avoid confusion for each case, a single common “root” day (and time) is absolutely necessary ... which must be set at a single location in a single time zone.

Here is just one example of this kind of potential confusion:  

In 2024, western Canadian media (in British Columbia) stated that the Spring Equinox arrived on Tuesday March 19th at 8:06 pm, whereas the BBC, broadcasting from London, England, stated that the Equinox arrived on Wednesday March 20th at 3:06 am.

So, in order to calculate the Lord’s calendar timings, Jerusalem is where the Israelites – including our Lord Jesus and His apostles – would have timed them from.  (Interestingly, Egypt, where the main calendar rules were initially revealed to Moses, shares the same time zone as Israel). 

However, we practically apply the timings at our own locations – i.e. beginning the same day and date as those at Jerusalem; but with our own, local sunset times. 

An Illustration for 2025

Following these solidly Bible-based rules, and keeping in mind that God’s days run from sunset to sunset (Genesis 1:8-31; Leviticus 23:32), here is what we believe to be the correct timing of the New Year’s Day of the 2025 Sacred Year, again, timed at Jerusalem:

◦ Vernal Equinox (at Jerusalem): 
     March 20th at 11:23 am

◦ The next “Lunar Conjunction” (New Moon) following the Vernal Equinox (at Jerusalem): 
     March 29th at 1:10 pm ... (N.B. prior to that day's sunset).

◦ The first day of the first month of the year (Abib 1) begins at the next Sunset following that Lunar Conjunction (at Jerusalem): 
     March 29th at 6:56 pm.

So, from these rules, here are the main, significant dates in God’s calendar for 2025 ... (showing the beginning and ending dates in the Gregorian calendar, because God’s days begin and end at sunset):

• First New Moon Day of the New Year: Abib 1: March 29-30
• Passover: Abib 14: April 11-12
• First Day of Unleavened Bread: Abib 15: April 12-13
• Last Day of Unleavened Bread: Abib 21: April 18-19 
• Wave Sheaf Offering Day: Abib 22: April 19-20  {Note 1}
• Pentecost: Siywan 12: June 7-8
 • Feast of Trumpets: Ethaniym 1: September 22-23
• Day of Atonement: Ethaniym 10: October 1-2
• Feast of Tabernacles: Ethaniym 15-21: October 6-7 to October 12-13
• Last Great Day: Ethaniym 22: October 13-14

It will be noted that, in some years, these dates fall in line with those of the mainstream Jews – from whom most mainstream Church of God groups obtain much – though not all – of their calendar timings.  {Note 2}  

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Note 1:  The morrow after the Sabbath Day that falls within the Feast of Unleavened Bread (per Leviticus 23:11-15). 

Note 2:  See Article on "the Oracles of God".

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