Christian Churches of God

No. CB20b





How to Determine

God’s Calendar


(Edition 1.0 20061106-20061106)


This paper explains the methods and rules of calculation used for determining God’s Sacred Calendar.



Christian Churches of God

PO Box 369,  WODEN  ACT 2606,  AUSTRALIA




(Copyright ã  2007 Jacques Guérard, ed. Wade Cox)


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How to Determine God’s Calendar


In this paper we will review the basic method, rules and calculations used to determine God’s Sacred Calendar and the First month of the New Year based on the astronomical New Moon conjunctions. These lunar cycles are well documented and all the calculated data can be found in official scientific sources such as NASA and others. Definitions for words used in determining the calendar are given the end of the paper for easy reference.


God’s Calendar is based on His creation – on His setting of the small and large luminaries. It is not based on anything of man’s creation, such as the modern Gregorian calendar or the Hillel Judaic calendar. God’s true Calendar is lunar-based, so it is determined from the lunar cycles, that is, the cycles of the moon. For a review of God’s Calendar see the papers God’s Sacred Calendar (No. CB20) and God’s Holy Days (No. CB22).


Firstly, we will review certain tables and data of moon conjunctions and spring equinoxes available from recognised scientific authorities. Secondly, we will examine the basic rules to determine the date of the New Moon to keep after converting the date from Universal Time (Greenwich Mean Time) to Jerusalem local time. Thirdly, we will use the spring equinox data to determine the date of the New Year or the beginning of the First month in the spring.


The establishment of the New Moon date for all localities and churches around the world is based on the date of the New Moon in Jerusalem. In this way a standard world calendar is possible. However, we keep the day of the New Moon and the Holy Days when it gets dark for us wherever we are living.


Isaiah 2:3 And many people shall go and say, Come ye, and let us go up to the mountain of the LORD, to the house of the God of Jacob; and he will teach us of his ways, and we will walk in his paths: for out of Zion shall go forth the law, and the word of the LORD from Jerusalem. (cf. also Micah 4:2).







We have a source of moon conjunctions at the following NASA web site:


All dates are based on the present Gregorian calendar and time in Universal Time (Greenwich). This data is used to determine the first day of the new month in God’s Calendar.




The equinox is the time when the sun crosses the plane of the Earth’s equator, making night and day all over the Earth nearly of equal lengths. This occurs on about March 20th or 21st and also 22nd September. The equinox helps us to determine the start of the year. If the 3:00 p.m. sacrifice of the 14th day of Nisan does not fall after the spring equinox, we intercalate or add a 13th month.


A source for data of spring equinoxes is available at the following U.S. Navy web site:


Following the same rule for the New Moons as above, we determine the day of the equinox to be 20th March, according to God’s definition.




The term End Evening Nautical Twilight (EENT) is the scientific term for the exact time that darkness begins in a specific location. This point is where a new day begins and the old day ends according to God’s creation. See the paper Start of the Month and the Day (No. 203). A table of times for EENT for Jerusalem can be computed for a period of one year – or 365 days – directly from the Internet web site using the following data: longitude East 35’ 19, latitude North 32’ 34, and 2 hours east of Greenwich.




A. Find the conjunction in the New Moon data.


Using the data for the moon conjunctions, we can determine the date of the New Moon day to be kept in Jerusalem. For example, we will determine the date of the New Moon for the First month of God’s Sacred Calendar in the year in 2008, or the 31st year of 120th Jubilee. We find the New Moon is at 17h14 in the table on 7 March 2008.


B. Determine the time of New Moon in Jerusalem local time.


We must convert the time of the New Moon conjunction shown in this table from Universal Time (UT) to Jerusalem local time by simply adding 2 hours. So we add 2 hours and obtain 19h14 (7:14 p.m.) for the local time of the New Moon in Jerusalem.


When adding 2 hours crosses over the midnight (00h00) point, we must adjust the date accordingly, that is, by making it the next day on the Georgian calendar. This is then the adjusted time of the data table.


C. Find the Jerusalem EENT in the 2008 chart.


For 7 March 2008, we find 18h34 (6:34 p.m.) in the EENT computed table using 2 hours east of Greenwich.


D. Adjust the date if the New Moon occurs between EENT and midnight 00h00.


In some cases, we need to adjust the date of the day to be kept since God’s natural day begins at dark while man set the beginning at midnight. There is thus a 6-hour difference between the two definitions that corresponds to the period between EENT in Jerusalem and midnight. However, in winter the day may end as early as 5:00 p.m. (17h00) and in summer it may end as late as 10:00 p.m. (22h00) in some parts of the world. The key point to remember here is that God’s day begins and ends at dark. For the purpose of explaining the concept of “from dark to midnight” we will refer to it as the 6-hour period, knowing that the time when it gets “dark” varies throughout the year.


So we can say God’s day begins and ends approximately 6 hours before man’s recent definition. When the New Moon occurs during this 6-hour period, we need to advance the date shown in the table to the following date to keep the day according to God’s definition. 


In our example, the date is changed to the next day to the table’s date because the time of the New Moon of 7 March occurred after the EENT of that day.


So, since the New Moon of 7 March 2008 occurs at 19h14 (7:14 p.m.), which is after EENT (18h34 or 6:34 p.m.), the New Moon is kept on March 8.




To determine which is the First month and First day of the year, we must find the New Moon closest to the spring equinox. The 14th of Nisan may coincide with the day of the equinox but would never be kept BEFORE the vernal equinox.  This is to prevent two Passover sacrifices occurring in the same calendar year. However, should the 14th occur before the equinox, a thirteenth month would be added to prevent this from happening.  Logically, it also means that the 15th of Nisan must always occur after the day of the equinox.


A. Find the time of the spring equinox.


In the tables for 2008 located at: the date of the vernal or spring equinox in the Northern Hemisphere is on March 20, at 05h48 UT. The vernal equinox occurs almost on the same date each year. We add 2 hours to determine local time in Jerusalem at 07h48. Following the same rule for the New Moons as above, we determine the day of the equinox to be March 20th according to God’s definition.


B. Find the New Moons before and after the spring equinox.


From the tables at, we find the date of the New Moon occurring just before the equinox day, March 20, and the New Moon occurring just after March 20. The New Moon day closest to the equinox becomes the new month of the New Year, which is the First day of the First month, called 1 Nisan or 1 Abib. In the year 2008, we have a New Moon on March 7th at 17h14UT (19h14 Jerusalem time) and a New Moon on April 6th at 03h55 (05h55 Jerusalem time). We find the New Moon on March 7th to be closest to the spring equinox of March 20th. Since this New Moon occurred at 19h14, after EENT (18h34) in Jerusalem and before midnight, we move the date to the next day. Thus, March 8th becomes the date of the First month of the year, i.e. the beginning of months and the beginning of the New Year, Nisan 1.


This is a summary of the method for determining God’s Calendar. All the dates of the New Moons and New Year Calendar can be found in the paper New Moon and Holy Day Calendar (C3).


May our Father and Creator Eloah teach all men about His Calendar so that all will worship Him as required and on the correct days.


See also the paper God’s Calendar (No. 156).




Definition of Terms:


Astronomical twilight: appears in the evening once the sun falls more than 18° below the horizon and disappears when the sun moves to within 18° of the horizon in the morning.


Conjunction: the meeting of heavenly bodies in the same longitude or right ascension, i.e. the situation of two or more heavenly bodies when their longitudes are the same – they appear to be in line with each other.


Civil twilight: begins in the morning when the centre of the sun is less than 6° below the horizon, and ends at sunrise. Evening civil twilight begins at sunset and ends when the center of the sun is more than 6° below the horizon.


EENT: End Evening Nautical Twilight is the exact time that darkness begins in a particular location.


Equinox: the equinox is the time when the sun crosses the plane of the Earth’s equator, making night and day all over the Earth of nearly equal lengths. This occurs twice during the year: once at the vernal or spring equinox about 20/21 March and once at the autumnal equinox about 22 September.

Greenwich Mean Time: mean solar time of the meridian through Greenwich, England.

Gregorian Calendar: the reformed Julian calendar introduced by Pope Gregory XIII and now in use. According to this calendar the ordinary year consists of 365 days (12 months), and 366 days in leap years. Days begin at midnight in the Gregorian calendar.


Intercalation: to intercalate means to insert an extra month to make the calendar year equal to the solar year.


Latitude: the angular distance north or south from the equator of a point on the Earth’s surface, measured in degrees.


Longitude: the angular distance east or west of the Earth’s surface, measured in degrees from a certain meridian (line from the North to the South Pole). Usually the meridian through Greenwich, England is used.


Lunisolar: relating to or based upon the relations or joint action of the moon and the sun (e.g. lunisolar cycle).


Lunisolar calendar: is a calendar whose date indicates both the moon phase and the time of the solar year. Usually there is an additional requirement that the year has a whole number of months, in which case most years have 12 months but every second or third year has 13 months. Seven times in 19 years we have a year with 13 months.


Moonrise/set times: these times depend on the phases of the moon – i.e. new moon at full dark, full moon and first and second quarters. The moon rises and sets each day just like the sun. For more information on the phases of the moon see:


Nautical twilight: defined as the time when the center of the sun is more than 6° below the horizon but less than 12°. This period in the morning is often referred to as “first light” before dawn, and in the evening as “nightfall” after dusk. Nautical Twilight is comparable to EENT.


New Moon: the astronomical New Moon, sometimes known as the dark moon, occurs by definition at the moment of conjunction in ecliptic longitude with the Sun, when the Moon is invisible from the Earth.


Solar time: measured or determined by the Earth’s motion in relation to the sun.


Sunrise: first appearance of the sun in the morning.


Sunset: the going down of the sun – the last appearance of the sun in the evening.


Universal Time: system of time measurement based on Greenwich Mean Time but counted from 0 hour, which is equivalent to midnight Greenwich Mean Time.