A Basic Guide to the Original Biblical Calendar:
Presented by The Refiner's Fire

Sadly, the calendar of the Bible has been made a mess by man! Nowhere in scripture does YHWH tells us how the calendar is to be formulated, so it has become a "free-for-all" with nearly everyone saying their calendar is "THE calendar of God" or even "The Creator's Calendar!" Many of those calendars simply "don't hold water" when push comes to shove! Even the traditional (modern) Hebrew calendar is fraught with issues resulting in most of YHWH's appointed times celebrated on the wrong days! My goodness! When the established calendar, accepted by Jews all over the world, has Passover in the entirely wrong lunar month (as truly happens some years) - that's as bad as it gets!

It bears repeating: Nowhere in scripture are we told how to determine the calendar! While there are a few scriptures which hint or suggest the rules of the calendar, no Scripture reveals how the year should be determined, none reveal how the month is determined, none say the "sighted crescent" begins the month, and none actually define the day as sunset-to-sunset! Every calendar determination is a "best guess."

Before continuing, let's briefly discuss the authority of the traditional calendar of Judaism (also called the "rabbinic calendar"). We acknowledge that the rabbinic calendar is the only authoritative calendar of Judaism. We acknowledge that any change to the calendar requires the express approval of the Great Sanhedrin. Unfortunately the Great Sanhedrin has not existed with the proper authority since the 2nd Temple's destruction in 70 CE and formally ceased to exist since 425 CE yet the "authorized" calendar has been changed many times since.

To get around the lack of a Great Sanhedrin, Judaism has determined instead that other bodies of rabbis have the authority. Given the spread of Jews all around the world, the rabbis decided the calendar needed to be "standardized" so the "proper" calendar could be known even to Jews in the diaspora. That's all well and good if it were not for the rules they chose in their calculations, calculations with negate the most important and central 2 verses in scripture from which the calendar is derived: Genesis 1:14 and Deuteronomy 16:1. The verse in Genesis commands that only the sun, moon, and stars determine the calendar and the verse in Deuteronomy commands that Passover be kept at the proper time to duplicate the conditions of the exodus.

Today's rabbinic calendar uses only the "average" moon, fixes the Solar Year on the wrong day, establishes Passover by a rigid rule using a 19 year repeating cycle, postpones the 1st day of Tishri based on man-made rules of convenience, and fixes the lengths of the months by rules. Needless to say, today's rabbinic calendar is a mess yet it is the "authorized" calendar of Judaism. The good thing is it is actually close to the calendar of the sun, moon, and stars but is getting more and more out-of-sync with the sun, moon, and stars as the centuries pass.

This article provides some "basics" as to how the calendar should be determined - based on scripture and the real sun, moon, and stars. Ready for the ride? Here goes:

Here are the basics, the essentials. For each item listed, a more thorough discussion/explanation follows.

  1. The calendar is to be established by the sun, moon, and stars. Period. This is in Genesis 1:14.
  2. The year is determined by the sun and stars.
  3. The lunar month ends and begins in darkness.
  4. The day is determined by the sun. This is sunset to sunset and is amply supported by scripture.
  5. The calendar month is determined by the moon and the first day of the Hebrew calendar month begins at the sunset after lunar conjunction*.

    *The "sighted moon", that is, waiting to spot the crescent to establish that sunset at the 1st day is quite wrong because by the time you see the crescent, the moon is already a day or two old and you clearly started the calendar month too late. The "day of conjunction" is wrong because you've started the month a day too early, and the new calendar month should not begin while the current lunar month has not yet ended. This would be akin to starting every "new day" at noon, hours before the sun has finished its "day"! The proper calendar attempts to "sync" the day (which is by the sun), to the month (which is by the moon). Therefore the moon must have been renewed (i.e., passed through conjunction) before the 1st day of the calendar can begin. Ideally, we'd begin the 1st day of each month at the same time as conjunction, but that is not possible. Thus the first calendar "day" must begin at the first sunset to follow the conjunction.
  6. Passover establishes the annual feast schedule and Passover is tied to the year determined by the sun, not the moon, and not the barley.
  7. We are blessed today with the ability to calculate calendar events, thus determining the calendar years in advance. But our modern computations must duplicate the signs of the sun, moon, and stars, which always were, and still are, the authorities, visible to all, including ancient man who could only rely on the evidence, seen and unseen - of these same authorites.
  8. The Sabbath is the 7th day each week, in perpetuity, never broken, and not tied to the moon!


  1. The calendar is established by the sun, moon, and stars. Period. This is in Genesis 1:14.

    Genesis 1:14 reads: "God said, "Let there be lights [luminaries] in the dome of the sky to divide the day from the night; let them be for signs, seasons, days and years;" (CJB). Is this not clear? Nothing in the verse even suggests that anything else, including the barley crop must be in the right stage of aviv (ripeness), so as to "hold off the year if the barley is not aviv"! The English word "seasons" in the verse is actually the Hebrew word "moedim", or "appointed times". The meaning of "appointed times" is absent in the English word "seasons" and has led many to err that the word "season" means Winter, Spring, Summer, and Fall. The moedim (appointed times) are defined special observances established in particular times of the year (Leviticus 23). The moed are tied to the agricultural seasons, yes, but not established by the crops, which is only an "earth sign". The verse in Genesis never clarifies which "sign" is for which event, but simply watching the sun, moon, and stars reveals the order (something most have forgotten today):

    The sun determines the day (refer to #4, below), as well as the year by its apparent position against the fixed background of stars (refer to #2). The month is established by the moon (refer to #5), and the "seasons" or "appointed times" are established in the particular calendar month in which they fall per Leviticus 23.
  2. The year is determined by the sun and stars.

    There are only four positions of the sun, in the heavens, as seen from our vantage point on the earth from which can be used as demarks for a "year". Today, we know these positions as the equinoxes and the solstices. Only the equinoxes are practical for determining the year because the exact day of an equinox is easy to determine by observation alone. (The solstices do not work well for the year because it is nearly impossible to know the exact day of the solstice by observation alone as the sun is observed to rise or set in virtually the same position (on the horizon) for 3-4 consecutive days.) The equinox identified to end/begin the year can be either the Autumnal (Fall) equinox or the Vernal (Spring) equinox - it really does not matter to man. But the Autumnal Equinox actually makes the most sense, because that period of the year marks the end of the harvests, and the beginning of the planting for the next year's crops. Indeed, the Autumnal Equinox would likely have been the start of the year for the ancient Hebrews, long before their captivity in Egypt. Nevertheless, there are no scriptures revealing exactly which point was used as the end/beginning of the year except...

    ...YHWH changed the identity of the "1st month" of the year for His people to the month of the exodus. This is recorded in Exodus 12:2. The exodus began when it was already the "month of the aviv" which means the Sun was already at that point when the crops planted the previous fall were turning green. That means the "month of the aviv" always fell in that part of the agricultural season determined by the sun, i.e. it was, indeed, springtime! YHWH says that month was to become the first month of the year for the Hebrews from then on.

    Note, this does not necessarily mean that the demark of the "year" was changed by Exodus 12:2. What? Think about it! YHWH commanded that the Hebrews recognize the month in which the exodus began, the month of Spring would be known as "their 1st month" of existence free from slavery. It does not state or even imply that the counting of years changed from what it was at that time! We see in Exodus 12:2 the word “ra’shon”, meaning “first in place, time or rank”, and it does not necessarily mean the “first” by count! (1st, by count is “echad”). So while Exodus 12:2 reads: “This month shall be unto you the beginning of months: it shall be the first month of the year to you” the actual meaning is that YHWH is telling them that this month, the month of the exodus shall rank “1st” to them from that time on.

    In Exodus 12:2, YHWH changed only the numbering of the months for the Hebrews to the month of their grand exodus. This is further supported by Exodus 12:14 & 17 where it is emphasized that the reason this month is so important and to be remembered forever as the "1st month" is because YHWH brought the Hebrews out of Egypt that very month. The counting of the years, which clearly already existed by some other month, did not change and did not need to change! Indeed, other scriptures require that the promised land lay fallow the 7th year, after the 6th year's crops are harvested. This can't happen in the Spring! This distinction of "years" is important. It seems that most believe that the year-count changed in Exodus 12:2 only because, in English, that's what it seems to imply.

    It's important also to understand that man would still have the "year" if the moon did not exist! And the earth would still have Winter, Spring, Summer, and Fall and all annual planting and harvesting would still be done in exactly the same annual cycle (though by watching only the sun against the stars). It is also important to understand that the method of establishing the year does not change if the moon were not present. This is why the Exodus 12:2 command to count the months from the month of Spring and keep Passover ties Passover to the sun, not the month to the crops! More on this in #6, below.
  3. The month ends and begins in darkness.

    This may sound a bit strange to many of you, but it's important to understand as it establishes what "sign" of the moon determines the 1st day of the month (refer to #6, below). The day, year, and month all "begin in darkness"! Again, that may sound strange so bear with me: Obviously, the day ends and begins in darkness. At sunset, the onset of darkness, the day ends, and the new day begins (in darkness), refer to #4, below. Not so clearly, the year can be understood to "end" in darkness. In Hebrew, one of the meanings of "Adar", which is the name for the last month of the Hebrew year of Moedim (appointed times), is “to darken”. So the end of the year of moedim "darkens", and the new year of moedim begins! (Not convincing, but interesting!)

    The sun is not visible when it is below the horizon, and no one argues that the "unseen sun" is not a "sign" of darkness! Yet many also say that a "sign" must be "visible" and conclude that the dark of the moon cannot, therefore, be a sign! I would agree, in most cases, a "sign" would typically need to be "visible", but in the case of the moon the requirement for visibility is nonsense! Here's why:

    The moon is always visible throughout the entire month at sometime during every day - except when it is at conjunction. (I have found this is something of which most people today simply are no longer aware.) So the very absence of the moon at the period of conjunction is the sign of conjunction (and conjunction is the time of the moon's renewal)! When the moon is not visible at all, it is a very clear sign of the calendar month! (So you can see that not all signs must be visible, and the claim is false!)

    (Sidebar: I have encountered at least one person who thinks Genesis 1:14 "declares" the month must begin at the sighted crescent moon. They claim that Genesis 1:14 requires "light" as the sign. But this is yet another example of an "English-only" understanding of scripture. Genesis 1:14 reads: “God said, 'Let there be lights in the dome of the sky to divide the day from the night; let them be for signs, seasons, days and years;' ” In Hebrew, the word translated into English as "lights" is "ma'rot" and means "luminous body, or luminary" and the word shown in English as "signs" is "l'atot", which means "signal, evidence, mark, or sign". It is clearly understood in Hebrew that this means there are many "signs" by these luminaries (the sun, moon, and stars), and in no way implies only "light" as a sign! And there certainly is no implication that the verse requires only "visible signs"! Thus, saying Genesis 1:14 "proves" a sighted crescent moon to begin the month is nonsense.)

    It is well known that in the Hebrew understanding, the moon is "renewed" at the time of conjunction. The Hebrew word "molad" means "birth" and very clearly the ancient Hebrews understood that the molad took place in the dark period of the moon and the "new month" was born. Today, the term "molad" has a specific meaning to the calculation of the modern Hebrew calendar but there can be no argument that the original "molad" of the moon would have been understood as the unseen "moment" of conjunction, the "birth" of the new month. Therefore, the "new month" is born in darkness!

    Indeed, darkness is very important to YHWH. The covenant with Avram was made in darkness (Genesis 15:7); Pesach (Passover) took place in darkness (Exodus 12:12); Yeshua rose in the dark (John 20:1). In fact, YHWH dwells in darkness (Exodus 20:21, 1 Kings 8:12, Psalm 18:11), and the very creation itself began in darkness, (Genesis 1:2), and ends in darkness (Revelation 20:11).

    (Don’t confuse this clear importance of darkness with the equal if not superior importance of light. Yahweh said: “Let there be Light”, and saw that it was good (Genesis 1:3-4), and Yeshua said He is the “light of the world” and that whoever followed him would not walk in darkness [meaning without hope] and have eternal life, (John 8:12). Indeed, light triumphs over dark (Revelation 21:23, 25). So both light and darkness have clear purpose and importance to Yahweh.)

    More detail is provided here and here, but for now realize that the end of the moon's month happens at a time when the moon is no longer visible, and the first day of the new calendar month (by the sun) must happen after the lunar conjunction.

    Conjunction is that invisible, unseen moment when the moon is renewed by its passing between the earth and the sun. As stated earlier, the moon is always visible, all month long, except when it is at conjunction, in darkness! Since the day is dictated by the sun, the absolute beginning of the new calendar month is tied to sunset, and the 1st sunset after conjunction is clearly the first opportunity to begin the calendar month. (It would be folly to begin the calendar month ON the day of conjunction, that is, at the sunset before conjunction because that would establish the calendar month by the sun and not the moon. But the moon establishes the month, so the moon must be renewed first, then the calendar month can begin!
  4. The day is determined by the sun.

    This should be a no-brainer for the sun clearly determines the day - no matter the definition of the "day"! But there are those who argue the day should be sunrise-to-sunrise, while others say it is "noon to noon" and the modern, civil calendar (with no relation to scripture) establishes it midnight to midnight! But what does scripture say?

    Scripture provides evidence that the (whole) day is determined as sunset to sunset. In Genesis 1 we find the description that "there was evening, and there was morning, one day", repeated as the day count of the creation continued to add days. While countless, endless arguments exist about the meaning of each word in Genesis 1 the fact remains that scripture conveys, in Hebrew, "evening [erev] and morning [boker] are one [echad] day [yom]." This is a pretty clear definition, almost as though there was intent in the words! Indeed, throughout the Tanakh, we find that sunset marked the end of the day, (Leviticus 23:32; Deuteronomy 21:22-23; Nehemiah 13:19; Judges 19:9, for example.) This truly should not be arguable. Only does modern man find that there is some argument as to when the day ends and begins.

    Though the definition of the day, sunset-to-sunset comes indirectly from scripture as just described, there is yet another reason for the "day" to be from sunset-to-sunset. It has to do with the month. Since the sun determines the day and the moon determines the month, and it is the visibility of the "new moon" which sanctifies (not defines) the new month has begun, one finds that there is no other demarcation of the day when the moon can be observed to validate the start the month! The 1st visible crescent which sanctifies the month has begun cannot, ever, be observed at sunrise! So if sunrise marked the new "day", one would never know the new month had begun until sunset, when the "day" was already half over! A sunset-to-sunset day is the only period of the solar day when the moon and sun can be that "echad" (one) event composed of the two separate signs.
  5. The month is determined by the moon and the first day of the Hebrew calendar month begins at the sunset after the unseen lunar conjunction.

    The very clear evidence that the "month" is determined by the moon is that the moon "reappears" 12 times in a solar year! This is indisputable. Therefore the "year" has always been divided into "12 months". (It is only coincidence with the "12 tribes" of Israel.) The division of the year into 12 months is the natural division of the year when watching how many "new moons" are observed in a solar year.

    [Sidebar: There are also clear apparent relationships to the number of days in a year (~365), and the number of degrees in a circle (360) which is evenly divided by 12 and that the number of days in a lunantion (29.5) is almost 30. But none of these connections are derived only from the sun, moon, and stars.]

    Mentioned above, many assume that the "1st visible crescent" marks the beginning of the 1st day of the month. Indeed, the vast historical evidence suggests that this misconception is pervasive. But there is no such requirement in scripture, and in fact, by the time anyone sees a new crescent, all it means is that it is a confirming sign that the month has already begun! By waiting to begin the month by the crescent, the entire remainder of the calendar month, fails to match the other monthly signs of the moon! (I'm well aware this concept is hard for many to accept. The idea that the month begins with the sighted crescent is so deep-seated in the faith that the simple idea that it is wrong is a hard pill to swallow!)

    Only by assessing the day of the unseen conjunction to establish the sunset which begins the new month will the calendar follow all the signs of the moon. This requirement is overlooked in almost all variants of the many "Hebrew calendars". The calendar should match all the signs of the moon! Why would a calendar, based on a single sign of the moon (i.e. the sighted crescent) be considered valid? Are the other signs invalid? If so, why? The greatest signs of the month are the beginning and the middle of the month! Only one of the annual moed occurs at the 1st of the month (Yom Teruah) but three of the most important moedim of the year occur at the middle of the month (Passover, Feast of Unleavened Bread, and Sukkot)! Ignoring the calendar for the moment, what event marks the middle of the "moon's month"? Why full moon of course!

    Without interference by biblical scholars, it is another "no-brainer" that if the calendar month is determined by the moon, then the 1st of the calendar month would be when the moon is "renewed" and the middle of the calendar month would be at the middle of the moon's month. Both the renewal and the middle of the moon's month are marked by clear signs! The end/beginning is marked by the absence of the moon and the middle is marked by the full moon! Why do most calendars ignore one of these two signs? (Centuries of "tradition" establishing the 1st day of the new month by the "sighted crescent" while the equally important sign of the middle of the month is completely ignored is no justification for the practice!)

    From #3, the only demonstrable method to establish the beginning of the month is the sunset after conjunction. Only by doing so are both the beginning and middle of the calendar month established to match the signs of the moon. If the 1st day of the month is established as the day of conjunction, then the middle of the calendar month precedes the day of the full moon, and if the 1st day of the month is established by the sighted moon, then the middle of the calendar month lags 1-3 days after the full moon. Again, the month must begin at the 1st sunset following conjunction. Of course, the objection is that since conjunction is unseen, how would it be known on which day was conjunction?

    It's rather simple actually. By watching the moon in the last days of the month, as the moon nears conjunction, many signs reveal the coming day of conjunction. Hence, we can always know, days in advance, which sunset after conjunction will be the 1st day of the month! This method is completely reliable and when needed, such as when the old crescent is not visible in the mornings before sunrise (due to clouds, for example), other signs of the moon reveal if the current month would be expected to be 29 or 30 days, and the day of conjunction can be estimated without additional observation.

    There are actually two visual methods, now long forgotten and overlooked, how the day of conjunction can be determined by observation alone. The first, already mentioned, is to simply continually watch the old crescent moon at the end of every month to build a visual "database" of how the moon looks in the last days of the month as a "pointer" to the day of conjunction. This is not so hard. When I was working, for 30+ years I was on the road every morning well before sunrise and I routinely watched the old crescent rise and came to be quite familiar with its many signs to make my own declaration of the day of conjunction. I found I was always correct, and it's not that hard to do.

    The second method is only a bit more involved. It requires determining the day of conjunction by the measurement of the "daily motion" of the moon in the 2-4 days before conjunction so you can compute the number of hours to conjunction from the time of the measurement. This technique is remarkably accurate, requiring only a visual measurement, with simple tools, to the nearest 1/2 degree (the apparent width of the moon itself), yet the technique is mostly forgotten. When you have computed the daily motion (simply the number of degrees the moon appears to move in one full day), you know not only the day but also the approximate hour of the unseen conjunction and it becomes a simple matter to know which sunset would be the 1st day of the new month! This technique was not beyond the capabilities of ancient people as it only requires measuring the apparent angle of the visible moon from the moment of sunrise. (One does not even need a clock!) Two or three mornings of gathering this information yields the day and estimated hour of the unseen conjunction quite accurate enough to establish the calendar!
  6. Passover establishes the annual feast schedule and Passover is tied to the year, not the moon, not the barley.

    Passover is the most important determinant of the calendar as that event sets all future commanded moedim for the year! I hope you are still with me! Before time of Exodus 12:2, the month of spring had already been established by a calendar which began in a different month (likely the Fall equinox)! The "month of the aviv" had NOT been established by the greening of the barley, rather, barely began to green because it was spring by the sun! That solidly means that the "month of the aviv" referred to the "month of spring" and probably not to a specific month called "Aviv". Rather, the phrase "month of Aviv" found in most versions of Exodus 13:4, 23:15, 34:18 and Deuteronomy 16:1 is actually Hebrew: "chodesh ha'aviv" and more properly translates to "month of the aviv" and not necessarily a month named "Aviv". The Hebrew letter "hey", which makes the sound of “ha”, added added to "aviv" as a prefix, is the equivalent to English article "the", so it is "the aviv", and not "Aviv" which most assume is the name of the month. Thus the event of Passover was tied to the Spring because spring had already happened when the exodus began (Exodus 12:2). Please think about that.

    So how do we know Passover was tied to the Vernal Equinox and not the moon? In Deuteronomy 16:1 we find: "Observe the month of [the] aviv, and keep Pesach to Adonai your God; for in the month of [the] aviv, Adonai your God brought you out of Egypt at night." (CJB). The "month of the aviv" was (and still is) established by the sun! When the sun has indicated springtime has begun, that time of the year when crops would begin to turn green, the calendar month necessarily must be the month of the aviv. If the calendar has the month of the aviv too early or too late, then it is the calendar that is wrong, for there is only one month of the year which can fall in season when the sun is indicating spring has arrived! So the charge to Moshe in Deuteronomy 16 was not to establish the "month of the aviv" to the sun, rather, is was to make sure that future observances of Passover happen on or after Spring as it was that year, the year of the exodus - because it is the Passover which is to be remembered forever (Exodus 12:14)!

    Thus the "rule" was established in scripture, by the command in Exodus 12:2 to make the month of the aviv the 1st month of the moed year. And the command in Deuteronomy 16:1 added to observe the month of the aviv and then keep the Passover at that time since Spring had already happened when the Exodus began. Therefore, that month (which today is called "Nisan") would be the month in which Passover could not be before the Vernal Equinox. The Vernal Equinox is the very definition of "spring" even in ancient times when it was called the "First Point of Aries" (because the Vernal Equinox actually happened in that age when the sun was in the constellation Aries). (In our time, the Vernal Equinox happens when the sun in Pisces.)

    It's worth reiterating. Many fail to see that it was not the new moon being anchored to the Vernal Equinox. Passover was fixed to the Vernal Equinox! Many also fail to see that the month of the aviv is not tied to the "ripening barley"! The ripening barley is only the result of the season established by the sun, clearly not the "determinant" of the calendar month! Thus the "rule" formed by this understanding is that since Passover is assigned to the exact middle of the month, the new moon closest to the Vernal Equinox establishes the "month of the aviv" (today Nisan). That keeps Passover on or after the Vernal Equinox, meeting the requirement of Deuteronomy 16:1.

    [Sidebar: I am well aware that the rabbis tied the importance of the ripeness of the barley to the need for a sheaf of grain for the Firstfruits offering on the 16th of Nisan. Therefore in the age before the calendar was computed, they established rules on when conditions of the barley would be considered to delay the start of the moed-year a month. But the fact is, this added condition "breaks" the commandment of Genesis 1:14 as it introduces both the barley and a condition imposed by man to establish the calendar which was clearly intended to be established only by the sun, moon, and stars.]
  7. We are blessed today with the ability to calculate calendar events, thus determining the calendar years in advance and not have to rely on observation. But our modern computations must duplicate the signs of the sun, moon, and stars, which always were, and still are, available to all, including ancient man who could only rely on the signs.

    This is important because if our modern calendar relies on some fact or feature which the ancients could not readily discern or measure, then our calendar is not the same as the calendar they would have used. Worse, if our calendar establishes Passover at an impossible time, as often happens with the modern, calculated traditional calendar, and the Karaite "barley" calendar, then the entire year's feast dates are automatically wrong - all of them falling an entire month late.

    Recognizing rule #6, establishing the proper date of Passover, goes a long way to establishing the proper moed calendar for the whole year. Of course, choosing the correct day for the first day of the month is also important, but slightly less so than the correct month of Passover.
  8. The Sabbath is the 7th day, in perpetuity, never broken, and not tied to the moon!

    This "rule" is included here only because the determination of the Sabbath has it's own controversial history. Some actually argue that the Sabbath, 7th day, is tied to the moon. But the 7th day Sabbath is clearly its own holy-day. It is in fact a defined, weekly, perpetual moed with YHWH. It is the 1st moed identified in Leviticus 23. It is clearly identified as completely separate from all other moedim (Leviticus 23:37-38). In Exodus 20:11; 31:17; and Leviticus 23:3 it is made clear that the 7th day of the week, not at all related to the moon, is the perpetual Sabbath. In this there should be no argument.

We at The Refiner's Fire are not naive enough to think this article actually "settles" the arguments of the calendar. We realize there are many learned scholars out there who will challenge the comments presented here by using the Talmud, Mishnah, Zohar, or the Kabbalah. But we stand by our conclusions that the sun, moon, and stars speak for themselves and that their many signs are still valid and available, today, for all to use if we would only take the time to learn them. The calendar must match the signs of the sun, moon, and stars or it is flawed.

Revised November 8, 2020