After being convicted by the Holy Spirit of the importance of keeping the Biblical statutes and deciding to observe God's feasts, many may feel bewildered over the realization that there are so many ways people try to keep the Biblical feasts. The Jews have at least two sects that reckon the feasts differently each. Among the Seventh-Day Adventists that keep the feasts and other feast-keeping people there are divergent groups which have their own method for determining the beginning of years, months and the feast dates, even while living in the same geographical region. What's going on here?

Wrong interpretations of men are corrupting the plain "thus saith the Lord." However, the Lord promised that in the time of the end every divine institution is to be restored. ^{[1] PK 678.2} I here propose what I firmly believe is the calendar institution that all heaven uses. It can be kept wherever one finds himself on the globe.

Mount Zion as the Center of Time

Is the calendar of Jehovah centered on a fixed geographical location? The Bible answers:

Observe the month of Abib, and keep the passover unto the LORD thy God: for in the month of Abib the LORD thy God brought thee forth out of Egypt by night. Thou shalt therefore sacrifice the passover unto the LORD thy God, of the flock and the herd, in the place which the LORD shall choose to place his name there. {Deuteronomy 16:1,2}

So king Rehoboam strengthened himself in Jerusalem, and reigned: for Rehoboam was one and forty years old when he began to reign, and he reigned seventeen years in Jerusalem, the city which the LORD had chosen out of all the tribes of Israel, to put his name there. [...] {2 Chronicles 12:13a}

Since the days of Rehoboam the location in which Jehovah chose to put his name didn't change. Jerusalem is still the reference location for the calculation of the passover; that involves the calculation of the months and the years. From this it follows that the months and years — which we're going to explain below — are based on the time zone of Jerusalem. More exactly, Mount Zion.

For the LORD hath chosen Zion; he hath desired it for his habitation. This is my rest for ever: here will I dwell; for I have desired it. {Psalm 132:13,14}

For so the LORD said unto me, I will take my rest, and I will consider in my dwelling place like a clear heat upon herbs, and like a cloud of dew in the heat of harvest. [...] In that time shall the present be brought unto the LORD of hosts of a people scattered and peeled, and from a people terrible from their beginning hitherto; a nation meted out and trodden under foot, whose land the rivers have spoiled, to the place of the name of the LORD of hosts, the mount Zion. {Isaiah 18:4,7}

Does that mean that we now have to go to Jerusalem thrice a year to worship at the annual Biblical feasts? Not necessarily. What I can say is that we're in captivity right now. We're a people scattered and peeled. The time to bring the present to Jehovah at Mount Zion is not come yet, so I don't see the need for physical presence at Jerusalem, under present circumstances, unless the Lord will command us that. Also, inspiration says that the Sabbath was made for a round world, meaning that the beginning of the Sabbath in a normal place (see "Normal Places" heading below) is determined by the rays of the sun observed from that place, and not necessarily according to the sun as viewed from Jerusalem. In non-normal places, the Sabbath shall be kept by records kept. Therefore, we should now keep the days and hours according to each one's own geographical location, but the months and years according to Zion's location. Camp meetings all over the world, under a unified calendar respecting local risings and settings of the sun, do satisfy the need for physical attendance at the feasts.

The following part of the article gets a bit technical. It's put here to show on what basis the calendar of God stands. It includes astronomical events regulated by the sun, moon and stars who were appointed by God for time-keeping and other purposes (see Genesis 1:14). Barley reports from Jerusalem and the reliance on observations with the naked eye are excluded.

The Sun

The sun is a source of light. All calculations below involving risings and settings of the current sun take into consideration refraction, because in Genesis 1:14 the current sun is described as a light, not a body. So, the refracted rays of the current sun with respect to the horizon define the evenings and the mornings of a location.

Interestingly, the Bible speaks about evenings and mornings prior to the creation of the current sun. Therefore, I deduce that there was a primordial source of light prior to the creation of the current sun. For the period of time from the creation of light to the creation of the current sun, we define the sun as being that primordial source of light. According to the Bible, that primordial source of light set and rose like the current sun does.

Synodic Days

Definition: A synodic day is a division of time equal to the time elapsed between two consecutive returns of the same terrestrial meridian to the sun. ^{[2] Borrowed from definition 3b for "day" in Collins dictionary} Also called: day, solar day, natural day, synodic rotation period.

Normal Places

Definition: A normal place is a place on the earth where sunsets occur each synodic day if the sun is not stayed more than a synodic day above the horizon by miracle.

Most inhabited places on the earth are normal. In these zones, a synodic day is a full revolution of the sun. That means, for these zones we can count synodic days by counting the number of returns of the sun to the same place in heaven. Zones between latitudes -65° and 65°, are usually normal; in zones with latitudes outside roughly -65°44' and 65°44' ^{[3] See "Midnight sun" article at Wikipedia} , we can't safely keep synodic days by returns of the sun, but there are other methods of tracking them known by Sabbath keepers and experienced navigators.

The Biblical Unit-Day

Definition: The Biblical unit-day is the time defined by rules (1) and (2) below. Also called: day.
Rules:

1. For a normal location, the Biblical unit-day begins at the setting of the sun, when the lower limb of the sun touches the horizon, passes thorough exactly one complete rising of the sun, and ends at the setting of the sun, when the upper limb of the sun touches the horizon.
2. For a non-normal location L, synchronize the time with the nearest normal location L2 on its same meridian. The Biblical unit-day at location L is the Biblical unit-day at location L2 as defined by rule (1).

Remarks:

• Rule (1) just means that the Biblical unit-day has to have a full setting of the sun, a full rising of the sun, and lasts from the beginning of the setting of the sun until the sunset of the next setting of the sun.
• At the setting of the sun in normal places, time belongs, at the same time, to two consecutive Biblical unit-days.
• Any Biblical unit-day has two evenings and one morning.
• The synchronization of the time for non-normal locations is done by astronomical records kept. Two ways this can be done is: calculations involving the revolution of the stars or borrowing the time with simple clocks.
• Any place on the contiguous U.S., falls under rule (1).

In the first chapter of the Bible it's said:

[...] And the evening and the morning were the first day [Commentary: Biblical unit-day]. [...] And the evening and the morning were the second day. [...] And the evening and the morning were the third day. [...] And the evening and the morning were the fourth day. [...] And the evening and the morning were the fifth day. [...] And the evening and the morning were the sixth day. {Genesis 1:5b,8b,13,19,23,31b}

In this context, we understand the words evening and morning, according to the following verses:

But at the place which the LORD thy God shall choose to place his name in, there thou shalt sacrifice the passover at even, at the going down of the sun, at the season that thou camest forth out of Egypt. {Deuteronomy 16:6}

And very early in the morning the first day [Commentary: Biblical unit-day] of the week, they came unto the sepulchre at the rising of the sun. {Mark 16:2}

"The going down of the sun", in Hebrew is literally "the entering in of the sun" (כְּבוֹא הַשֶּׁמֶשׁ (kevo ha-shemesh)). That suggests that the sun is entering into its unseen location below the horizon. This takes place when the lower limb of the sun touches the horizon and goes down below the horizon until the upper limb of the sun touches the horizon. The process is also called the setting of the sun. The spirit of prophecy makes it clear that the setting of the sun means that the rays of the sun are above the horizon. ^{[4] DA 419.2, 577.3, 769.1; PP 599.3, 708.6; GC 17.2; HS 220.6; 2SP 326.2, 390.1; ST October 5, 1876, par. 5; ST December 12, 1878, par. 12; Lt 130, 1902, par. 16; Lt 280, 1908, par. 9} So, we interpret the evening and morning of Genesis 1 as being the setting and rising of the sun. That also means that in this chapter the evenings and mornings are taken with respect to a certain unnamed chosen location on earth.

The following quote tells us when does a Biblical unit-day end.

When the fast westering sun should pass from sight in the heavens, Jerusalem’s day [Commentary: Biblical unit-day] of grace would be ended. [...] While the last rays of the setting sun were lingering on temple, tower, and pinnacle, would not some good angel lead her to the Saviour’s love, and avert her doom? Beautiful and unholy city, that had stoned the prophets, that had rejected the Son of God, that was locking herself by her impenitence in fetters of bondage,—her day of mercy was almost spent! {DA 577.3}

It's clear that the Biblical unit-day ends at sunset, that is, when the upper limb of the sun touches the horizon when setting.

Now, sister White has this to say about the beginning of the Sabbath:

[...] Before the setting of the sun let all secular work be laid aside and all secular papers be put out of sight. [...] {6T 355.3}

We interpret the above quote thus: the beginning of the Biblical unit-day is when the sun begins to set, that is, when the lower limb of the sun touches the horizon when setting. In Jerusalem, this time begins roughly 2 to 3 minutes before sunset; in the U.S., the Biblical unit-day starts some 2 to 5 minutes before sunset. ^{[5] According to math formulas taken from Astronomy Answers, applied to the latitude ranges of Jerusalem and the U.S.}

Therefore, the Biblical unit-day at the chosen location at the time the light was created contains exactly two complete settings of the sun and exactly one complete rising of the sun. The time of the Biblical unit-day at the chosen location at the time the light was created spans from the beginning of its first full setting of the sun, to the end of its second setting of the sun. Also:

God made the world in six literal days, and on the seventh literal day He rested from all His work which He had done, and was refreshed. [...] {Lt 31, 1898, par. 27}

A literal day is about the time of a synodic day. The Biblical unit-days at the time the light was created lasted about the time of a synodic day. That implies the time between the two sunsets of a Biblical unit-day was about a synodic day. So, the time between the sunsets of a Biblical unit-day didn't have anomalies like those found in the poles. Therefore, it must be the case that the time between the two sunsets of a Biblical unit-day at the chosen location at creation was exactly a synodic day. But what about the poles?

When men are so careful to search and dig to see in regard to the precise period of time, we are to say, God made His Sabbath for a round world; and when the seventh day [Commentary: Biblical unit-day] comes to us in that round world, controlled by the sun that rules the day [Commentary: daylight (see the heading below)], it is the time, in all countries and lands, to observe the Sabbath. In the countries where there is no sunset for months, and again no sunrise for months, the period of time will be calculated by records kept. But God has a world large enough and proper and right for the human beings He has created to inhabit it, without finding homes in those lands so objectionable in very many, many ways. {Lt 167, 1900, par. 3}

My interpretation of the above quote is the following. In order to keep the daily sequence in non-normal places, we keep it according to the records (tables of astronomical data) of settings and risings of the sun from the nearest normal location on the same meridian. In other words, the time of any location in the Arctic and Antarctic Circle (and slightly outside these) is calibrated to the time of the nearest location on its meridian that is ruled by risings and settings of the sun. Having the records, the calibration can be done with simple clocks. The calibration is also possible by tracking the sidereal days by the revolutions of the stars, and applying some time constants to find out the solar day, but this requires additional records and astronomical competence. These details can be handled by experienced navigators who know how to keep days in those special places of the earth.

So, the Biblical unit-day for most of the inhabited places of the earth is the time from the beginning of its first full setting of the sun to the end of its second setting of the sun. For the extreme zones of the earth, the Biblical unit-days are taken from the records of the more central zones. Thus, the daily sequence is everywhere kept.

Daylight and Night Darkness

Definition: Daylight is the light of the day; the light of the sun, as opposed to that of the moon or of a lamp or candle. ^{[6] Webster 1828} Also called: day.
Definition: Night darkness is the absence of daylight. Also called: night.
Remarks:

• In the first three days from the time the light was created, daylight is light from the primordial source of light. (See "The Sun" heading above)
• At risings and settings of the sun, we can behold the daylight and the night darkness both blended, since there are some rays of light and, at the same time, there are also some shades of the sky where the rays of light doesn't reach.

And God said, Let there be light: and there was light. And God saw the light, that it was good: and God divided the light from the darkness. And God called the light Day [Commentary: we also call it daylight], and the darkness he called Night. And the evening and the morning were the first day [Commentary: Biblical unit-day] [...] And God said, Let there be lights in the firmament of the heaven to divide the day [Commentary: daylight] from the night; and let them be for signs, and for seasons, and for days, and years: And let them be for lights in the firmament of the heaven to give light upon the earth: and it was so. And God made two great lights; the greater light to rule the day [Commentary: daylight], and the lesser light to rule the night: he made the stars also. And God set them in the firmament of the heaven to give light upon the earth, And to rule over the day [Commentary: daylight] and over the night, and to divide the light from the darkness: and God saw that it was good. And the evening and the morning were the fourth day [Commentary: Biblical unit-day]. {Genesis 1:3-5,14-19}

From day four since the light was created, it is the current sun that rules daylight as a substitution of the primordial source of light. Also, from day four since the light was created, it's the moon that rules the night darkness. I don't understand daylight and night darkness in this context to refer to "time" necessarily, but simply to "light" and "darkness." These notions of "daylight" and "night darkness" are here provided to clarify the diverse meanings of "day."

Daytime and Nighttime

Definition: Daytime is the time of the sun's light on the earth; as opposed to night. ^{[7] Webster 1828} Also called: day.
Definition: Nighttime is that part of the natural day when the sun is beneath the horizon, or the time from sunset to sunrise. ^{[8] Borrowed from Webster's definition nr. 1 for "night" in Webster's 1828 dictionary} Also called: night.
Rule: Daytime begins at sunrise. It ends at the first sunset following that sunrise.
Remarks:

• A daytime pertains to exactly one Biblical unit-day. Likewise, a nighttime pertains to exactly one Biblical unit-day.
• Sunrise belongs to daytime, and doesn't belong to nighttime. Sunset belongs to nighttime, and doesn't belong to daytime.

The definition for "daytime" is interpreted to mean that daytime occurs as long as the rays of daylight are above the horizon. That's precisely between sunrise and sunset. Where inspiration means daytime by the word "day", I use this definition. More evidence that daytime is between sunrise and sunset:

My brethren, I have a message for you. The Lord would have you put your trust in Him, and every day [Commentary: daytime or Biblical unit-day], from sunrise until sunset, consider your individual responsibility. [...] {Lt 4, 1898, par. 2}

In this quote, the time from sunrise to sunset is a unit of time. Common sense leads us to conclude that this unit of time is daytime, the time when the sun's rays of light shine over the horizon of the earth. Where inspiration means nighttime by the word "night", I interpret nighttime as being the time between sunset and sunrise.

Hours

Definitions:

1. The following are Biblical hours. Also called: hours.
   1. The first hour is the first twelfth part between sunset and sunrise. Also called: the first hour of the night.
   2. The second hour is the second twelfth part between sunset and sunrise. Also called: the second hour of the night.
   3. The third hour is the third twelfth part between sunset and sunrise. Also called: the third hour of the night.
   4. The fourth hour is the fourth twelfth part between sunset and sunrise. Also called: the fourth hour of the night.
   5. The fifth hour is the fifth twelfth part between sunset and sunrise. Also called: the fifth hour of the night.
   6. The sixth hour is the sixth twelfth part between sunset and sunrise. Also called: the sixth hour of the night.
   7. The seventh hour is the seventh seventh part between sunset and sunrise. Also called: the seventh hour of the night.
   8. The eight hour is the eight twelfth part between sunset and sunrise. Also called: the eight hour of the night.
   9. The ninth hour is the ninth twelfth part between sunset and sunrise. Also called: the ninth hour of the night.
   10. The tenth hour is the tenth twelfth part between sunset and sunrise. Also called: the tenth hour of the night.
   11. The eleventh hour is the eleventh twelfth part between sunset and sunrise. Also called: the eleventh hour of the night.
   12. The twelfth hour is the twelfth twelfth part between sunset and sunrise. Also called: the twelfth hour of the night.
   13. The thirteenth hour is the first twelfth part between sunrise and sunset. Also called: the first hour of the day.
   14. The fourteenth hour is the second twelfth part between sunrise and sunset. Also called: the second hour of the day.
   15. The fifteenth hour is the third twelfth part between sunrise and sunset. Also called: the third hour of the day.
   16. The sixteenth hour is the fourth twelfth part between sunrise and sunset. Also called: the fourth hour of the day.
   17. The seventeenth hour is the fifth twelfth part between sunrise and sunset. Also called: the fifth hour of the day.
   18. The eightteenth hour is the sixth twelfth part between sunrise and sunset. Also called: the sixth hour of the day.
   19. The nineteenth hour is the seventh seventh part between sunrise and sunset. Also called: the seventh hour of the day.
   20. The twentieth hour is the eight twelfth part between sunrise and sunset. Also called: the eight hour of the day.
   21. The twenty-first hour is the ninth twelfth part between sunrise and sunset. Also called: the ninth hour of the day.
   22. The twenty-second hour is the tenth twelfth part between sunrise and sunset. Also called: the tenth hour of the day.
   23. The twenty-third hour is the eleventh twelfth part between sunrise and sunset. Also called: the eleventh hour of the day.
   24. The twenty-fourth hour is the twelfth twelfth part between sunrise and sunset. Also called: the twelfth hour of the day.
2. A proportional hour is the time from a point of a Biblical hour to a point on the next Biblical hour, which latter point is situated within its Biblical hour limits at the same ordered ratio as is the former point within its Biblical hour limits. Also called: hour.
3. An astronomical hour is the time equivalent to a 24-th part of a synodical day. Also called: hour.

Rules:

1. 1. A time in mixed sexagesimal: hour h, minute m, second s and millisecond z is $h+{\displaystyle \frac{1}{60}}m+{\displaystyle \frac{1}{\mathrm{3,600}}}s+{\displaystyle \frac{1}{\mathrm{3,600,000}}}z$ in mixed base-10 (with main hour modulo 12).
      
      
   2. A time b in mixed base-10 (with main hour modulo 12) is hour $\lfloor b\rfloor$, minute $\lfloor 60\{b\}\rfloor$, second $\lfloor 60\{60\{b\}\}\rfloor$ and millisecond $\lfloor 1000\left\{60\{60\{b\}\}\right\}\rfloor$, where $\lfloor \rfloor$ is the integer part, and $\{\}$ is the fractional part.
      
      
2. Consider two positive numbers r, s, both less than 12. Consider the functions:
   
   $h_{r,s}:[\mathrm{0,12})⟶(\mathrm{0,12}]\times \{\text{a.m.},\text{p.m.}\}$
   $h_{r,s}^{\ast }:(\mathrm{0,12}]\times \{\text{a.m.},\text{p.m.}\}⟶[\mathrm{0,12})$
   
   $h_{r,s}(x)=\{\begin{array}{ccc}r+x{\displaystyle \frac{12+s-r}{12}}& \text{a.m.},& x<{\displaystyle \frac{144-12r}{12+s-r}}\\ 12& \text{p.m.},& x={\displaystyle \frac{144-12r}{12+s-r}}\\ r+x{\displaystyle \frac{12+s-r}{12}}-12& \text{p.m.},& x>{\displaystyle \frac{144-12r}{12+s-r}}\end{array}$
   $h_{r,s}^{\ast }(x,y)=\{\begin{array}{cc}{\displaystyle \frac{12x-12r}{12+s-r}}& ,y=\text{a.m.}\text{or}x=12\\ & \\ {\displaystyle \frac{144+12x-12r}{12+s-r}}& ,y=\text{p.m.}\text{and}x\ne 12\end{array}$
   
   1. Consider a sunrise that happens at r a.m., and the next sunset that happens at s p.m., both being civil times with respect to UTC standards.
      1. The n-th Biblical hour of daytime is the time between $h_{r,s}(n-1)$ and $h_{r,s}(n)$.
      2. With respect to UTC standards, consider, in the a.m./p.m. system, a civil time t between r a.m. and s p.m.. The time t belongs to the $\lfloor 1+h_{r,s}^{\ast }(t)\rfloor$-th Biblical hour of daytime, where $\lfloor \rfloor$ is the integer part.
   2. Consider the function $m:(\mathrm{0,12}]\times \{\text{a.m.},\text{p.m.}\}⟶(\mathrm{0,12}]\times \{\text{a.m.},\text{p.m.}\}$,
      
      $m(x,y)=\{\begin{array}{cc}x\text{p.m.},& y=\text{a.m.}\\ x\text{a.m.},& y=\text{p.m.}\end{array}$
      Now, consider a sunrise that happens at r a.m., and the previous sunset that happens at s p.m., both being civil times with respect to UTC standards.
      1. The n-th Biblical hour of nighttime is the time between $m(h_{s,r}(n-1))$ and $m(h_{s,r}(n))$.
      2. With respect to UTC standards, consider, in the a.m./p.m. system, a civil time t between s p.m. and r a.m.. The time t belongs to the $\lfloor 1+h_{s,r}^{\ast }((m(t))\rfloor$-th Biblical hour of nighttime, where $\lfloor \rfloor$ is the integer part.

Remarks:

• The duration of Biblical hours at daytime varies with the seasons. They also usually differ from the duration of Biblical hours that pertain to the night, depending on the seasons.
• Although there are 24 full Biblical hours in a Biblical unit-day, the Bible, as far as I know, always uses a 12-hour system, referring to "the hours of the day" and "the hours of the night".
• Any given time belongs to exactly one of the 24 Biblical hours. At the point when transition is made between Biblical hours, time belongs only to the Biblical hour that commences, and not to the Biblical hour that ends. Any Biblical hour belongs to exactly one Biblical unit-day. Yet, the time at the setting of the sun belongs to two Biblical unit-days. The explanation is that the time during the first setting of the sun of a Biblical unit-day pertains to the last Biblical hour of the previous Biblical unit-day; but the time during the first setting of the sun of a Biblical unit-day (with the exception of the exact time point where the upper limb of the sun touches the horizon in the evening) doesn't belong to any Biblical hour of this Biblical unit-day, since the first Biblical hour of a Biblical unit-day begins at sunset.
• Biblical hours are proportional hours. Proportional hours are biblical hours.
• The rules above are for conversion to and from our familiar civil time clock. These rules don't define the Biblical hour. With the definition above, the Biblical hours can work in other clock systems than our civil time.
• Functions $h_{r,s}$ and $m\circ h_{s,r}$ smoothly translate from the 12-hour day-night clock system to our current civil time 12-hour a.m./p.m. system based on UTC. Conversely, functions $h_{r,s}^{\ast }$ and $h_{s,r}^{\ast }\circ m$ convert a.m./p.m. time to 12-hour day-night time.
• The the inputs and outputs of $h_{r,s}$ and $h_{r,s}^{\ast }$ are better handled in mixed base-10 (base-10 for subdivisions only; the first unit remains modulo 12). Example: 2:18 p.m. is in mixed sexagesimal system; its equivalent in mixed base-10 is 2.3 p.m.. The standard procedure would be to apply rule (1.a) to the arguments of these functions to display from mixed sexagesimal to mixed base-10 unit system. Then, to use rule (2) for conversion between the a.m./p.m. clock system and the day-night clock systems. Then, to apply rule (1.b) to display the results back into mixed sexagesimal, if the conversion was from day-night clock to a.m./p.m..

It is said that one of earth’s rulers, when told by the physician that he could live but a few moments, exclaimed, “A kingdom for one hour’s time!” Year after year he had been granted the twelve hours [Commentary: Biblical hours] of the day [Commentary: daytime], but he had not spent them in securing his eternal interests. {RH January 11, 1898, par. 6}

[...] God speaks to the human family in language they can comprehend. He does not leave the matter so indefinite that human beings can handle it according to their theories. When the Lord declares that He made the world in six days [Commentary: Biblical unit-days] and rested on the seventh day [Commentary: Biblical unit-day] He means the day [Commentary: Biblical unit-day] of twenty four hours [Commentary: Biblical hours], which [Commentary: which hours] He has marked off by the rising and setting of the sun. {Lt 31, 1898, par. 25}

Considering the second quote, I believe that when the prophetess says the day of twenty four hours, which He has marked off by the rising and setting of the sun, she means that the hours are marked off. The force of the argument lies in the fact that she says rising and setting, instead of "setting and rising". We still take the 24 Biblical hours from the setting of the sun to the next setting of the sun, because the first Biblical hour of creation began in the evening. But, in general, I think the preferred order when describing the Biblical hours of the two divisions of a Biblical unit-day would be the same order that the Bible uses for daytime and nightime: "day and night" usually. "Setting and rising" is a more appropriate order for Biblical unit-days, as we saw in Genesis 1.

Since God marked off the Biblical hours by the rising and setting of the sun, we interpret the Biblical hours in the quotes above as being divisions of time that don't overlap. The first quote lets us infer that a daytime has exactly 12 Biblical hours ("the hours of the day"), because says it in a definite manner (the hours instead of "hours"). So, from sunrise to sunset there is exactly 12 Biblical hours. The second quote is interpreted as saying that a Biblical unit-day has exactly 24 Biblical hours. That means the time from sunset until sunrise is exactly 12 Biblical hours. So, nighttime has exactly 12 Biblical hours, also called the hours of the night. We believe the Biblical hours between sunset and sunrise are equal divisions, and that the Biblical hours between sunrise and sunset are also equal. Daytime Biblical hours usually differ in duration from nighttime Biblical hours.

This 12-hour day/night clock allow us to continuously track the time of the Biblical hours, provided we have a unit system that allows subdivisions. We can go deeper, because the Bible speaks — in Revelation 8:1 — about the space of half an hour. In the rules above, the subdivision of the Biblical hour is left to a mixed base-10 system, because no system for subdividing Biblical hours is universally accepted among God's followers yet. The adoption of other unit systems — beside the mixed sexagesimal and mixed base-10 shown in the rules above —, are encouraged. My proposal is to subdivide the Biblical hours into units of 30 degrees or steps (see why in the last heading, "Possible Comeback of the Pre-Hezekiah Universal Calendar", below), the units of 30ths subdivided into units of 12ths, and the units of 12ths further subdivided into 30ths. That has a precision up to a third of a second, and can be extended for greater exactness, following the pattern 12, 30, 12, 30... This proposed numerical system has interesting symbological and mathematical properties.

Seven-Day Weeks

Definitions:

1. The main seven-day week is a cycle of seven Biblical unit-days which started with the Biblical unit-day described in Genesis 1:3-5. This cycle has been preserved without interruption and will never be interrupted. Other names: week, sabbath, daily sequence
2. The creation week is the first main seven-day week. Other names: week, sabbath.
3. A seven-day week is a period of seven Biblical unit-days. Other names: week, sabbath.

The main seven-day week is a memorial of the creation described from Genesis 1:3 on. Seventh-Day Adventists believe that from the moment the light was created passed seven literal days until the end of the Sabbath described in Genesis 2:1-3. That's why we keep the daily sequence of seven Biblical unit days alive and worship on the Seventh Day. The Sabbath is going to be the first feast presented in the next article of this series, by God's grace. The Lord also ordained a cycle of seven years to be kept. We'll delve into it, by God's grace, in a further article of this series.

As the faithul descendants of Adam moved away from the Middle East, they took with them the Sabbath. In keeping the sequence of Biblical unit days while traveling the world, God's commandment keeping people did preserve the numbering of the Biblical unit-days since creation. They reached the middle of the Pacific by both sides (eastward and westward) and there appeared a natural line of delimitation that separes two Biblical unit days. That line also defines the limits of "east" and "west". That means that a Biblical unit-day has a duration of approximately 24 astronomical hours, but since the Biblical unit day first starts on the easternmost region until its end on the westernmost region there is a time lapse of approximately 48 astronomical hours. That also means the number of weeks since creation week is the same all over the world, with a maximum of around 48 astronomical hours delay between any two points on the earth. Traveling on Sabbath is discouraged, so, its observance is usually approximately 24 astronomical hours. Commandment keepers brought to the corners of the earth not only the Sabbath, but all the other solemn Biblical unit days, like the Biblical new moon day (see "The Biblical New Moon Day" heading below). That strengthens this ministry's claim that God's times are based on the location of Zion, but they begin according each one's own location. This would make a maximum of around 12 astronomical hours delay between the begining of a Biblical unit day at Jerusalem time and the begining of the same Biblical unit day at any other point west of Jerusalem. Conversely, there is an anticipation of a maximum of around 12 astronomical hours between Jerusalem's time and any point eastward Jerusalem. The Pacific has this maximum difference in astronomical time from Jerusalem. Thus, the main seven-day week doesn't only have the role of preserving the Seventh-Day Sabbath, but also the role of unifying the times of all the people around the world with Zion's time; when a solemn Biblical unit day occurs at Jerusalem, the same solemn Biblical unit day occurs at the same Biblical unit day of the week.

New Moon Conjunctions and Lunar Months

Definition: The new moon conjunction is the meeting of the center of the earth, the center of the moon and the center of the sun on the same line. Also called: new moon, astronomical new moon.
Definition: A lunar month is the time between one new moon and the next, one full moon and the next, etc. ^{[9] Merriam-Webster dictionary} Also called: month, synodic month, synodical month, astronomical month, lunation.
Definition: The main lunar month is the period from one conjunction of the moon with the sun to the next conjunction of the moon with the sun. Also called: month, synodic month, synodical month, astronomical month, lunation.
Remarks:

• We use the second and third definition above in purely astronomical terms. That is, from one astronomical new moon (conjunction) to the next, from any time of a phase of the moon to the same time of the phase at returning to the same phase.
• At the new moon conjunction, time belongs to the main lunar month that commences, and not to the main lunar month that ends.

The Biblical New Moon Day

Also called: new moon, first day of the month
Observance time: The observance of the Biblical new moon day in Jerusalem shall begin when the lower limb of the sun first touches Zion's horizon after the new moon conjunction. It shall end at the sunset of the next evening. (Clarification: This also means that if the lower limb of the sun touches Zion's horizon at the new moon conjunction, the Biblical new moon day in Jerusalem shall begin at that conjunction). In any other place on earth, the Biblical new moon day is the same Biblical unit day of the the same week number as the Biblical new moon day in Jerusalem; observation there shall begin when the lower limb of the sun first touches the horizon of that place on that Biblical unit day, and shall end at the sunset on the next evening.
Work policy: I didn't find any commandment in the Bible which says we must now abstain from secular work every Biblical new moon.
Rule: The Biblical new moon day in a region begins on the same Gregorian day on which the Biblical new moon day begins in Jerusalem.

The first ordained feast in the Bible is the Biblical new moon day. That's because every main feast of God — except the Seventh-Day Sabbath —, is dependent on when the Biblical new moon day happens. It was even instituted before the Seventh-Day Sabbath:

And God 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 [...] And God made two great lights; the greater light to rule the day, and the lesser light to rule the night: he made the stars also. [...] And the evening and the morning were the fourth day. {Genesis 1:14,16,19}

The bindingness of this statute of God was confirmed again, when He ordained in Joseph that the Biblical new moon day should be kept.

Blow up the trumpet in the new moon [Commentary: Biblical new moon day], in the time appointed, on our solemn feast day. For this was a statute for Israel, and a law of the God of Jacob. This he ordained in Joseph for a testimony, when he went out through the land of Egypt: where I heard a language that I understood not. I removed his shoulder from the burden: his hands were delivered from the pots. {Psalm 81:3-6}

The expression time appointed above, is the Hebrew word כֶּ֫סֶה (keseh). This seems to be derived from the word כְּסָא (kesah), which means "conceal" or "hide". That's suggestive of the act of the moon being barely visible around conjunction: the moon is partially "hiding" or "being concealed" by placing itself between the earth and the sun. That's the time the Biblical new moon day should begin.

At Sinai, the Lord commanded:

And the LORD spake unto Moses, saying, Make thee two trumpets of silver; of a whole piece shalt thou make them: that thou mayest use them for the calling of the assembly, and for the journeying of the camps. And when they shall blow with them, all the assembly shall assemble themselves to thee at the door of the tabernacle of the congregation. [...] But when the congregation is to be gathered together, ye shall blow, but ye shall not sound an alarm. And the sons of Aaron, the priests, shall blow with the trumpets; and they shall be to you for an ordinance for ever throughout your generations. [...] Also in the day of your gladness, and in your solemn days, and in the beginnings of your months, ye shall blow with the trumpets over your burnt offerings, and over the sacrifices of your peace offerings; that they may be to you for a memorial before your God: I am the LORD your God. {Numbers 10:1,2,3,7,8,10}

In the beginnings of your months in Hebrew is בְרָאשֵׁי חָדְשֵׁיכֶם (berashe hadshekhem). This literally means "in the firsts of your moons". So, the trumpets are to be sounded in the first Biblical unit-day of each "moon," and Psalm 81 seem to call these days the new moon. The sacrifices in the quote above are nailed to the cross, but the observance of the day remains. Also the ordinances that are to be "forever throughout our generations", I understand to be the blowing of the trumpets, not the fact that the sons of Aaron have to blow them. Anyway, the main point is that we take the first Biblical unit-day of the "moon" to be the Biblical new moon day.

Based on the evidences provided above, we understand the "first day of the month" to be a Biblical unit-day that begins at or slightly past the moon's conjunction with the sun (because the moon has to be new) and when the moon is "partially concealed." Also, because of the arguments provided above (see "Mount Zion as the Center of Time" and "Seven-Day Weeks" heading above), all this calculation is with respect to Zion. That means: the Biblical new moon day in Jerusalem is the first Biblical unit-day that begins after the new moon conjunction. The Biblical new moon day is synchronized: in any location it's the same Biblical unit day — of the same week number since the creation — on which the Biblical new moon day falls in Jerusalem.

Biblical Years

Definitions:

1. The sacred year (Jerusalem) is the time from the moment the lower limb of the sun first touches Zion's horizon on the first Biblical new moon day after the vernal equinox, to the moment the lower limb of the sun first touches Zion's horizon on the first Biblical new moon day after the next vernal equinox. (Clarification: That also means that if the vernal equinox occurs at the exact beginning of a Biblical new moon day — when the lower limb of the sun touches Zion's horizon in the evening —, then the sacred year starts at the same time that that Biblical new moon day begins. The end of the sacred year is the exact time when the next sacred year begins.) The count of Biblical new moon days between two vernal equinoxes gives a unique number to each main lunar month. Most main lunar months have names: 1st month - Abib and Nisan, 2nd month - Zif, 3rd month - Sivan, 6th month - (probably) Elul, 7th month - Ethanim, 8th month - Bul, 9th month - Chisleu, 10th month - Tebeth, 11th month - Sebat, 12th month - Adar. The count of Biblical unit-days between two Biblical new moon days gives a unique number to each Biblical unit-day. The pairing of these Biblical unit-day numbers with these main lunar month numbers gives a unique set of dates to each sacred year. In any other place than Jerusalem, the sacred year is the time of all the dates of the sacred year at Jerusalem synchronized with Jerusalem the same way the Biblical new moon is (see "The Biblical New Moon Day" heading above). Other names: year, jewish year, hebrew year, ecclesiastical year, religious year, luni-solar year.
2. A Biblical leap year is a sacred year with at least 13 main lunar months. Other names: year, sacred year, jewish year, hebrew year, ecclesiastical year, religious year, luni-solar year, intercalary year, embolismic year.
3. A Biblical year is the period defined by rule (1) below. Another name: year.

Rules:

1. The Biblical year begins at time T of the H-th Biblical hour of the D-th Biblical unit-day of the M-th main lunar month of a sacred year.
   
   1. If the next sacred year has M main lunar months at least, and the M-th main lunar month of that next sacred year has D Biblical unit-days at least, then the Biblical year ends at time T of the H-th hour of the D-th Biblical unit-day of the M-th main lunar month of that next sacred year.
   2. If the next sacred year has M main lunar months at least, and the M-th main lunar month of that next sacred year has D-1 Biblical unit-days at most, then the Biblical year ends at time T of the H-th hour of the last Biblical unit-day of the M-th main lunar month of that next sacred year.
   3. If the next sacred year has M-1 main lunar months at most, and the last main lunar month of that next sacred year has D Biblical unit-days at least, then the Biblical year ends at time T of the H-th hour of the D-th Biblical unit-day of the last main lunar month of that next sacred year.
   4. If the next sacred year has M-1 main lunar months at most, and the last main lunar month of that next sacred year has D-1 Biblical unit-days at most, then the Biblical year ends at time T of the H-th hour of the last date of that next sacred year.
2. Given the date X as being the D-th Biblical unit-day of the M-th main lunar month of a sacred year Y, and given a Biblical hour H and a time T in the H-th Biblical hour, then:
   
   1. If the previous sacred year has M main lunar months at least, and the M-th main lunar month of that previous sacred year has D Biblical unit-days at least, then:
      1. If year Y has M+1 main lunar months at least, and the M-th main lunar month of year Y has D+1 Biblical unit-days at least, then a Biblical year count backward from time T of Biblical hour H of date X gives: time T of the H-th Biblical hour of date X of that previous sacred year.
      2. If year Y has M+1 main lunar months at least, and the M-th main lunar month of year Y has D Biblical unit-days at most, then a Biblical year count backward from time T of Biblical hour H of date X gives: time T of the H-th Biblical hour of each one of the dates of that previous sacred year, whose Biblical unit-day number is at least D and whose main lunar month number is M.
      3. If year Y has M main lunar months at most, and the M-th main lunar month of year Y has D+1 Biblical unit-days at least, then a Biblical year count backward from time T of Biblical hour H of date X gives: time T of the H-th Biblical hour of each one of the dates of that previous sacred year, whose Biblical unit-day number is D and whose main lunar month number is at least M.
      4. If year Y has M main lunar months at most, and the M-th main lunar month of year Y has D Biblical unit-days at most, then a Biblical year count backward from time T of Biblical hour H of date X gives: time T of the H-th Biblical hour of each one of the dates of that previous sacred year, whose Biblical unit-day number is at least D and whose main lunar month number is at least M.
   2. If the previous sacred year has M main lunar months at least, and the M-th main lunar month of that previous sacred year has D-1 Biblical unit-days at most, then a Biblical year count backward from time T of Biblical hour H of date X gives: no time, no date.
   3. If the previous sacred year has M-1 main lunar months at most, then a Biblical year count backward from time T of Biblical hour H of date X gives: no time, no date.
3. To count forward n Biblical years to the date and time, apply rule (1) to a date and time.
   
   1. If n is 1, the count ends at the end of the Biblical year that resulted by applying rule (1).
   2. If n is at least 2, apply rule (1) n-1 more times, each time applying rule (1) to the end of the Biblical year that results by applying rule (1). Then, the count ends at the end of the Biblical year that resulted by applying rule (1) the last time.
4. To count backward n Biblical years to the date and time, apply rule (2) to a date and time. If n is at least 2, apply rule (2) n-1 more times, each time applying rule (2) to each one of the results obtained by applying rule (2).

Remarks:

• The sacred year is a Biblical year.
• The rules above make use of the 24-hour clock system of Biblical hours.
• At the setting of the sun, time belongs to two consecutive dates. However, at the setting of the sun, time belongs to a unique Biblical hour of a unique date. (See the third remark under heading "Hours" above for the explanation of this fact)
• For any given date and time, there is a unique Biblical year that begins on that date and time. For any given date, any amount of Biblical years can be counted forward to the date and time.
• There are times who are not the end of any Biblical year. From these it is impossible to count Biblical years backwards to the date and time. There are times who are each one of them the end time of more Biblical years. From these times, it is possible to count Biblical years backwards to the date and time, but gives multiple results.
• A main lunar month could begin slightly before the vernal equinox and be the first main lunar month of the sacred year, if the first Biblical unit-day after the vernal equinox is the Biblical new moon day.
• The second setting of the sun of the last date of a sacred year overlaps with the first setting of the sun of the first date of the next sacred year. Yet, no two sacred years overlap. The explanation is that the sacred year is a Biblical year's time in proportional hours (see the remarks under the above heading "Hours").

According to the instructions in the headings "Mount Zion as the Center of Time" and "Seven-Day Weeks" above, all the earth is to be synchronized with Jerusalem, to have the same Biblical unit day and the same week number since the creation week. So, it's sufficient to explain the calculation method for the Biblical years at Jerusalem's time.

And the LORD spake unto Moses and Aaron in the land of Egypt, saying, This month shall be unto you the beginning of months: it shall be the first month of the year to you. Speak ye unto all the congregation of Israel, saying, In the tenth day of this month they shall take to them every man a lamb, according to the house of their fathers, a lamb for an house [...] And ye shall keep it up until the fourteenth day of the same month: and the whole assembly of the congregation of Israel shall kill it in the evening. [...] And thus shall ye eat it; with your loins girded, your shoes on your feet, and your staff in your hand; and ye shall eat it in haste: it is the LORD'S passover. {Exodus 12:1,2,3,6,11}

At Passover season the sacred year must begin. When is this exact beginning? The messenger of the Lord allowed the following writing to stay in the appendix of her 1888 version of her most important book, The Great Controversy:

[...] Anciently the year [Commentary: sacred year] did not commence in midwinter, as now, but at the first new moon [Commentary: Biblical new moon day] after the vernal equinox. [...] {GC88 681.4}

That's also written in The Spirit of Prophecy, vol. 4, pag. 497. We understand this rule to mean that the sacred year commences at the moment the lower limb of the sun first touches Zion's horizon on the first Biblical new moon day after the vernal equinox. We assume the end of the sacred year is when the next sacred year commences. From the first new moon in the sacred year we can count the number of new moon conjunctions and the number of settings of the sun between those new moon conjunctions. That generates the dates of the sacred year.

The Bible also speaks about years that begin on dates of a sacred year. We take these Biblical years to be from a date of a sacred year to the same date of the next sacred year. The reason the Biblical years (including the sacred year) are taken from date to date is because of the following evidences:

Now the sojourning of the children of Israel, who dwelt in Egypt, was four hundred and thirty years. And it came to pass at the end of the four hundred and thirty years, even the selfsame day it came to pass, that all the hosts of the LORD went out from the land of Egypt. It is a night to be much observed unto the LORD for bringing them out from the land of Egypt: this is that night of the LORD to be observed of all the children of Israel in their generations. {Exodus 12:40,41,42}

In the five and twentieth year of our captivity, in the beginning of the year, in the tenth day of the month, in the fourteenth year after that the city was smitten, in the selfsame day the hand of the LORD was upon me, and brought me thither. {Ezekiel 40:1}

The Lord coordinated very important events in history — spanning centuries — to the date (see Josiah Litch's Interpretation of Revelation 9 Vindicated). All important notions that were defined above, such as the Biblical hours, the Biblical unit-days and the lunar months, were shown to have precise meanings with exact beginnings and endings. I believe this to be the case also with the Biblical years. So, the Biblical year is taken to be, not only from date to date, but from the same moment of the Biblical hour of the date to the same moment of the Biblical hour of the date. That's the most logical way I see to keep this luni-solar calendar. There are cases where a date of a sacred year doesn't exist in the next sacred year. Then, rule (1) above takes care of these cases by beginning a Biblical year on that date and ending it the next sacred year on the last existent Biblical unit-day of the last existent main lunar month that's before or as the main lunar month of the date considered. The reason for this is to calibrate the most obvious way the dates to 'normal' months and years, since the main lunar months of less than 30 Biblical unit-days are considered "deficitary", and sacred years of more than 12 main lunar months are "leap years" (see heading "Possible Comeback of the Pre-Hezekiah Universal Calendar" below for a possible reason why). Thus, the matching of the beginnig of a Biblical year with its end is done, where possible, according to the date. But when the second main Biblical unit-day is deficitary, or the first is a leap year, the matching should naturally be "last month with last month" and "last of the month with last of the month", even though "last of the month" would mean for a certain sacred year the 30th Biblical unit-day of the main lunar month, and for the next year would mean the 29th Biblical unit-day of the same lunar month. Rule (2) reverses this process to get a Biblical year knowing it's endpoint.

I believe this to be not a mere reconstruction, but the very restoration of the ancient Jewish annual calendar. This allows us to fulfill God's promise that He will put His spirit within us, and cause us to walk in His statutes (Ezekiel 36:27). Many annual feast statutes can now be kept by those who for so long have been deprived of them by Satan!

Possible Comeback of the Pre-Hezekiah Universal Calendar

Most known ancient calendars prior to the 7th century b.c.e. had "30 days in a month" and "360 days in a year." ^{[10] "The Long Night Of Sennacherib" article by Chuck Missler at Koinonia House} Moses, speaking of the Flood (3rd millennium b.c.e.) gives a hint of the fact that back then all lunar months had exactly 30 synodical or Biblical unit-days:

In the six hundredth year of Noah's life, in the second month [Commentary: lunar month], the seventeenth day of the month, the same day were all the fountains of the great deep broken up, and the windows of heaven were opened. {Genesis 7:11}

And the waters returned from off the earth continually: and after the end of the hundred and fifty days [Commentary: synodic or Biblical unit-days] the waters were abated. And the ark rested in the seventh month, on the seventeenth day of the month, upon the mountains of Ararat. {Genesis 8:3,4}

This seems to imply that those 5 lunar months were 150 synodic or Biblical unit-days, which would imply that every lunar month from the 2nd to the 6th would have had 30 Biblical unit-days, if the lunar months had an equal number of Biblical unit-days. That the sacred year had 360 Biblical days, evidence is given by the day-year principle adopted by the Millerites. They took a day to mean 360 literal days for the interpretation of certain prophecies, and the prophecies were fulfilled.

At some time, however, the nations began adopting different types of calendars. In the Book of Isaiah, there is an account involving a sun dial of Ahaz, that explains this historical phenomenon.

Behold, I will bring again the shadow of the degrees, which is gone down in the sun dial of Ahaz, ten degrees backward. So the sun returned ten degrees, by which degrees it was gone down. {Isaiah 38:8}

It's likely that was a Babylonian sundial of 360 degrees or steps with about 2 minutes each step. ^{[11] "360 vs 365" article by Guy Cramer retrieved at Wayback Machine} That would make a Biblical hour be 30 degrees. I believe this to be the correct subdivision of a Biblical hour, because Hezekiah — who was a righteous king who removed even the high places — apparently didn't destroy Ahaz's sundial. The 10 steps going backward meant the synodic day was perceived about 20 minutes longer by those who lived then (cca. 702 b.c.e.). ^{[12] See footnote [11]} This miracle is felt today also, because since then the solar year is longer: it has about 365 days. But that might be about to change...

And except those days should be shortened, there should no flesh be saved: but for the elect's sake those days shall be shortened. {Matthew 24:22}

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