To be upfront, no, this isn’t a take on Kamala Harris’ speech in 2022 in which she mentioned the phrase “the significance of the passage of time” four times in a short span. This is a little different and hopefully more significant. This article is about time and how it is reckoned by the Metonic Cycle, the Hebrew calendar, and the sun, moon, and stars.
“Now a great sign appeared in heaven: a woman clothed with the sun, with the moon under her feet, and on her head a garland of twelve stars” (Revelation 12:1).
Two calendars are used to determine the passage of time, and both are celestial. The first one is the solar calendar which is determined by the sun’s positioning. The summer solstice, the longest day of the year (from the point of view of the northern hemisphere), and the day when the sun is at its highest point in the sky mark the passage of a year.
In ancient times, this could be measured by erecting monuments (such as Stonehenge) or other rock structures, a testament to the historical and cultural significance of timekeeping. The same is true for the winter solstice, the year’s shortest day. There are approximately 365.2422 days in a solar calendar because that’s how long it takes for the Earth to orbit the sun.
As Earth revolves around the Sun, there are two moments each year when the Sun is exactly above the equator. These moments are called equinoxes. One occurs around March 19-21 (in the northern hemisphere) and is called the vernal equinox because it signals the beginning of the astronomical spring season. Vernal means fresh or new. The other equinox occurs around September 22-23 and is called the autumnal equinox because it marks the first day of the astronomical fall or autumn season. Equinox means “equal night” since the length of day and night is nearly equal in all parts of the world during the equinoxes.
The other celestial calendar is the lunar or moon calendar, which follows the monthly cycles of the moon’s phases. It’s one of the oldest calendars in the world that creates lunar months, also known as synodic months. A lunar month is simply one that occurs between two successive syzygies, such as new moons and or moons. The word month is derived from the word moon.
“God said, Let there be lights in the firmament of the heavens to divide the day from the night; and let them be for signs and seasons, and for days and years” (Genesis 1:14).
On average, there are approximately 29.53 days between each moon phase (new moon – new moon, etc.). A lunar year is approximately 354 days, so it loses 11-12 days annually compared to the solar calendar. However, ancient civilizations found practical applications for the lunar calendar using the moon’s phases to help identify the seasons (Spring, Summer, Autumn, and Winter). Since each season has at least three full moons, this instructed them on when to schedule necessary activities like harvesting and hunting. The moon calendar was used for ritual and religious purposes and still is today. Easter, Rosh Hashanah, Ramadan, and the Chinese New Year are just a few holidays or feast days that rely on the (moon) lunar calendar.
“He appointed the moon for seasons; The sun knows its going down” (Psalm 104:19).
The Jewish religious calendar is a combination of the lunar and solar calendars. It is called a lunisolar calendar. The conjunction of the new moon (dark moon) determines a new month. Usually, the first day (or second) after the dark moon will be the first day of the new month on the lunisolar calendar. The middle of the month (14-16) will occur on a full moon. This is when the start of the Passover begins. A month will have 29-30 days, and a year will have 353-355 days. Typically, there are 12 months to a year, but an intercalary month (30 days) is added every 2-3 years to keep the harvests and religious activities (Feasts of the Lord) in their proper seasons. Over time, the lunisolar calendar, with the added intercalary months, will have the same number of days as the solar calendar.
One of the methods used by the ancient Greeks to achieve lunar-solar harmony was the Metonic cycle, named after the Greek astronomer Meton, who lived in the 5th century BC. The Metonic cycle is a period of 19 years, after which the lunar phases recur at the same time of the year. The recurrence is not perfect, and by precise observation, the Metonic cycle defined as 235 synodic months is just 2 hours, 4 minutes, and 58 seconds longer than 19 tropical years. The lunar month is when the Moon completes one cycle of phases, from the New Moon to the New Moon. This cycle was found to be a nearly exact match for 19 solar years (19 years x 365.2422 days = 6939.6 days). Over time (approximately 200-300 years), it will drift by one day.
By incorporating the Metonic cycle into their calendar system, the ancient Greeks could synchronize the lunar and solar calendars for an extended period, ensuring that important religious and agricultural events occurred at the appropriate times.
Mathematical calculations played a crucial role in developing and implementing the Metonic Cycle. These mathematical calculations determined the accuracy and duration of the Metonic Cycle. By aligning the solar and lunar calendars, the Metonic Cycle ensured that the phases of the moon and the seasons of the year remained synchronized. This synchronization was achieved by adding seven intercalary months (30 days) to the 19-year cycle, compensating for the fractional difference between the lunar and solar years. The mathematical genius behind the Metonic Cycle allowed for an accurate and practical calendar system.
“Ancient Greek farmers relied on the Metonic cycle to determine their agricultural practices. The Metonic cycle, based on the lunar-solar connection, played a crucial role in determining the most favorable times for planting and harvesting crops, demonstrating the practical benefits of the lunar-solar connection in everyday life. This connection allowed farmers to synchronize their agricultural activities with natural phenomena such as lunar phases and solar seasons. By observing the patterns of the moon and the sun, farmers could accurately predict the optimal periods for planting different crops, ensuring a successful harvest.
Moreover, the Metonic cycle also influenced the religious calendar of the ancient Greeks, as many religious festivals were closely tied to agricultural events. These festivals celebrated the cycles of planting, growth, and harvest, reflecting the deep connection between agricultural practices and the spiritual beliefs of Greek society.
The legacy of the Metonic cycle can be seen in various modern calendars that use a lunisolar system. One example is the modern Hebrew calendar, which incorporates the Metonic cycle to ensure the alignment of the lunar and solar years. This allows for the observance of religious holidays, such as Passover and Yom Kippur, to fall on the exact dates each year consistently. Another example is the Islamic calendar, which also utilizes the Metonic cycle to reconcile the lunar and solar calendars. This is particularly important for determining the dates of Islamic holidays, such as Ramadan and Eid al-Fitr.” (1)
However, the Greeks weren’t the first civilization to use this calendar type. The ancient Babylonians and Hebrews also employed a lunar-solar calendar. The ancient Hebrew calendar was not calculated mathematically but relied on nature and celestial objects. “Blow the trumpet at the time of the New Moon, At the full moon, on our solemn feast day” (Psalm 81:3).
Initially, the first of every month and year was during the first new moon of fall, but God changed it to spring in the time of Moses. The original Passover occurred in Egypt during Moses’ time before the Hebrews’ exodus occurred. To convince Pharaoh and the Egyptians to let the Hebrew people go, God sent ten plagues upon Egypt. The seventh plague was when the LORD sent hail mixed with fire to all the land of Egypt, except in Goshen, where the Hebrews lived. Exodus 9 says it was so heavy that there was none like it in all the land of Egypt since it became a nation. “And the hail struck throughout the whole land of Egypt, all that was in the field, both man and beast; and the hail struck every herb of the field and broke every tree of the field” (Exodus 9:25).
We know Abib (now known as Nisan) occurred in the early spring because of the following verse: “Now the flax and the barley were struck, for the barley was in the head, and the flax was in bud. But the wheat and the spelt were not struck, for they are late crops” (Exodus 9:31-32). The month of the exodus was the month of the “Abib” (or Aviv) crops, the month of the year in which the crops were already known to begin to turn green each year. “And Moses said to the people: Remember this day in which you went out of Egypt, out of the house of bondage; for by strength of hand the Lord brought you out of this place. No leavened bread shall be eaten. On this day you are going out, in the month Abib” (Exodus 13:3-4).
The wheat, coming out of the ground later, was now tender and hidden, either under the ground or in the herb, whereby it was secured both from the fire by its greenness and moisture and from the hail by its pliableness and yielding to it: whereas the stalks of barley were more dry and stiff, and therefore more liable to be injured and destroyed by the fire and hail. In Egypt, the wheat harvest is at least a month later than the barley harvest, which is finished by the end of March or April.
“We know from several passages that barley which is in the state of Aviv has not completely ripened but has ripened enough so that its seeds can be eaten and parched in fire. Parched barley was a commonly eaten food in ancient Israel and is mentioned in numerous passages in the Hebrew Bible as either “Aviv parched (Kalui) in fire” (Lev 2,14) or in the abbreviated form “parched (Kalui/ Kali)” (Lev 23:14; Jos 5:11; 1Sam 17:17; 1 Samuel 25:18; 2 Samuel 17:28; Ruth 2:14).
While still early in its development, barley has not yet produced large enough and firm enough seeds to produce food through parching. This early in its development, when the “head” has just come out of the shaft, the seeds are not substantial enough to produce any food. At a later stage, the seeds have grown in size and have filled with liquid. At this point, the seeds will shrivel up when parched and will only produce empty skins. Over time, the liquid is replaced with dry material, and when enough dry material has amassed, the seeds will be able to yield barley parched in fire.
The month of the Aviv is the month which commences after the barley has reached the stage of Aviv. 2-3 weeks after the beginning of the month, the barley has moved beyond the stage of Aviv and is ready to be brought as the “wave-sheaf offering” (Hanafat HaOmer). The “wave-sheaf offering” is a sacrifice brought from the first stalks cut in the harvest and is brought on the Sunday which falls out during Passover (Chag HaMatzot). This is described in Lev 23:10-11,
“When you come to the land which I give you, and harvest its harvest, you will bring the sheaf of the beginning of your harvest to the priest. And he will wave the sheaf before Yehovah so you will be accepted; on the morrow after the Sabbath the priest will wave it.”
From this, it is clear that the barley, which was Aviv at the beginning of the month, has become harvest-ready 15-21 days later (i.e. by the Sunday during Passover). Therefore, the month of the Aviv cannot begin unless the barley has reached a stage where it will be harvest-ready 2-3 weeks later. If the barley is not developed enough so that it will be ready for the sickle 2-3 weeks later, then the month of the Aviv cannot begin, and we must wait till the following month.” {2}
The wave-sheaf offering, known as the Feast of First Fruits to most Bible scholars, must occur after Passover (Nisan 14) and within the seven days of the Feast of Unleavened Bread. During the remaining days of the Feast of Unleavened Bread (after the waving of the barley sheaf), the barley bread to be consumed was made without leaven. This is why First Fruits must be within the Feast of Unleavened Bread. In the Torah, leaven represents sin. The bread represents Jesus’ body, which was without sin. Barley is the first crop to rise from the earth in early spring. Jesus is the first fruits of the first harvest to rise from the earth to eternal life with a translated eternal body. “But now Christ is risen from the dead, and has become the firstfruits of those who have fallen asleep” (1 Corinthians 15:20).
Shortly after the seventh plague and before the tenth and final plague, God told Moses and Aaron, “This month shall be your beginning of months; it shall be the first month of the year to you” (Exodus 12:1). The LORD changed the “counting of months” from the first month of fall to the first month of spring so the first calendar month of the year would now coincide with the month of the Hebrew’s new-found freedom – the month of the exodus. However, the “counting of years” would remain with the original fall calendar (the civil calendar).
The LORD informed Moses and Aaron regarding the tenth and final plague, the Passover plague, in which He would kill all the firstborn (man and beast) of Egypt. The LORD instructed Moses and Aaron on how to avoid the same fate as the Egyptians with the blood of the Passover lamb. The first Passover (and all God’s instructions regarding it) and subsequent days of eating only unleavened bread for seven days are described in Exodus 12:1-29).
In Deuteronomy 16:6, the LORD reiterated, “You shall sacrifice the Passover at twilight, at the going down of the sun, at the time you came out of Egypt.” At the original Passover, in 1446 BC, God changed the Hebrew calendar’s start so it would be permanently anchored to the Passover when the children of Israel came out of Egypt.
“Let the children of Israel also keep the passover at his appointed season. In the fourteenth day of this month, at even, you shall keep it in his appointed season: according to all the rites of it, and according to all the ceremonies thereof, shall you keep it” (Numbers 9:2-3). “The appointed season was the beginning of spring. The sun still determined the season, as the calendar’s first month would always occur around the vernal equinox (the first day of the astronomical spring) when the early barley crops were abib or aviv. The new moon would still begin the months, and approximately 14-16 days later, when the moon was completely full, the Passover would begin. Thus, Passover is tied to the vernal equinox and the full moon.
However, you no longer watch for the day of the new moon to begin the year; instead, you assess which new moon establishes the proper day of the Passover to begin the annual remembrance! Therefore, the rule to determine the month of the abib crops (modern Nisan) is the new moon that establishes Passover on or after the Vernal Equinox. This is the same as saying the first month (Nisan) is the new moon closest to the Vernal Equinox (whether the new moon is before or after the Vernal Equinox). No other rules are added.” (3)
This biblical Hebrew calendar was still in use in Jesus’ time. The moon was observed and not mathematically calculated. The crops were also observed for readiness to harvest. If the crops were in “aviv” during the first new moon of spring, that was the year’s first month. If the crops were not “aviv,” then an extra 13th month was added to the calendar, and the first month (Abib or Nisan) of the new year would occur on (or 1-2 two days later) the second new moon conjunction of spring (late March or April).
After the Jews were forced out of the land of Israel in 135 AD and could no longer determine their calendars, as they couldn’t observe the heavenly signs from Jerusalem any longer (nor determine their crop’s readiness for harvest), they eventually developed a mathematically calculated calendar based on the 19-year Metonic (intercalation) cycle.
In the fourth century AD, Hillel II established a fixed calendar based on mathematical and astronomical calculations (similar to Meton’s). This calendar, still in use, standardized the length of months (29-30 days) and the addition of months so that the lunar calendar realigns with the solar years over the course of a 19-year cycle. The modern (calculated) Hebrew calendar relies on seven intercalary months within the Metonic cycle so that religious holidays and planting/harvests fall in their appropriate seasons, whereas the Islamic calendar does not. The 13th month (embolismic or intercalary), Adar I, is added to the cycle’s 3rd, 6th, 8th, 11th, 14th, 17th, and 19th years. We are currently, in 2024, in the 9th cycle.
The modern Jewish “calculated” calendar is still used today for religious purposes. It is quite ingenious but is not as accurate as the ancient observed calendar and has many flaws. Also, through the centuries, many rules have been added by the rabbinic Jews that are not biblical. Below are just a few of them:
- Pesach: The Passover begins on 15 Nisan and lasts for seven days in Israel and eight days outside Israel. It can only begin on Monday, Tuesday, Thursday or Saturday.
- Shavuot: The Feast of Weeks falls on 6 Sivan or 7 Sivan outside Israel. It can only fall on Monday, Tuesday, Thursday or Sunday.
- Rosh Hashanah: The Jewish New Year falls on 1 Tishrei. It can only fall on Monday, Tuesday, Thursday or Saturday.
- Yom Kippur: The Day of Atonement falls on 10 Tishrei. It can only fall on Monday, Wednesday, Thursday or Saturday.
- Sukkot: The Feast of Tabernacles begins on 15 Tishrei and lasts seven days. It can only begin on Monday, Wednesday, Friday or Saturday.
- Certain months are restricted to 29 days, while others are restricted to 30 days. A few of them can be either.
The Hebrew Metonic cycle of 19 lunar years, which includes seven intercalary months, equals 6939 days. This is equivalent to 19 solar years. For example, the first day of the first month in 2016 was Nisan 1 on the Jewish calendar and April 9, 2016, on the Gregorian calendar. The end date (6,939th day) will be April 9, 2035. The following day, April 10, 2035, will be Nisan 1 on the first year of the next Metonic cycle.
Nisan 1, or April 9, 2016, is approximately two days past that year’s second new moon of spring (meteorological spring). Nisan 1, 2035, is also two days past the second new moon of April 8, 2035. The question arises: Why is Nisan 1 reckoned by the second new moon of spring instead of the first one for these years? The answer lies within the preceding year of the 19th year of the previous Metonic cycle. The 19th year is an embolismic year (3, 6, 8, 11, 14, 17, 19) of 383-385 days. The 19th year was calculated from March 21, 2015, to April 8, 2016 (384 days). The first spring new moon of 2015 occurred on March 20th.
So, 2016-2017 is a regular (352-355 days) year because it is year 1 on the current Metonic cycle. For this to be true regarding the rules of the calculated Jewish calendar, the starting date for this year was April 9, 2016, and the end date was March 27, 2017 (352 total days). March 27, 2017, is actually one day ahead of the first new moon of March.
April 9, 2016, is very late for a Nisan 1 date. That would put the ‘waving of the omer” (First Fruits of barley) on April 24th as reckoned by the biblical dating for this event. I wrote about this in Calculated Jewish Calendar vs. Biblical Jewish Calendar:: By Randy Nettles – Rapture Ready. There is no reason (other than the Metonic cycle rules) that Nisan 1, 2016, shouldn’t have started during the first (meteorological) spring new moon instead of the second one.
The first new moon conjunction occurred on March 9th of that year, and the full moon conjunction occurred on March 23rd. The new moon determines the date of Nisan 1, and the full moon determines Passover. The Feast of Firstfruits (waving of the barley omer) and Shavuot/Pentecost do not get Jewish dates until Nisan 1 is determined. Regarding Gregorian calendar dates, none of the Feasts of the Lord get dated ahead of time until Nisan 1 is determined. Of course, with the calculated Metonic calendar Israel currently uses, this is no problem.
The vernal equinox (the first day of the astronomical spring) occurred on March 20, 2016, so Passover (Nisan 14) would have been after the vernal equinox. March 9, 2016, the first new moon of spring, is closer to the vernal equinox than April 7, 2017, the second new moon of spring; therefore, the first date should have been used. You (the Jews) do not want to wave the barley sheaf during the Feast of First Fruits (waving of the barley omer) if it is too ripe, as it will just fall apart. It is also necessary to begin harvesting the crops as soon as possible.
I always knew the calculated Jewish calendar could be off by a few days because of these rules. Still, I didn’t realize until recently that it might be off by a month from the astronomically Biblical calendar. This error occurs more often in the modern Hebrew calendar as the centuries progress. This problem is well recognized, even in modern Judaism. “Applying the Metonic cycle to the Hebrew calendar is perfectly fine over the whole 19-year cycle, but it is wrong to apply the “rules” of the Metonic cycle by its rigid schedule of intercalation within any 19-year period. The actual moon should declare which year should be the intercalary year, not a rigid, predetermined schedule!
The modern, authoritative calendar of Israel applies the rigid but erred Metonic cycle to their calendar, while the Biblical calendar only intercalates when Passover would naturally fall at the time of the Vernal Equinox. We have seen in recent years that the modern, Calculated calendar of Judaism is more and more divergent from the real sun, moon, and stars. In some years, the date of Passover and all commanded moedim as determined by the authorized calendar fall in the wrong lunar month. 2016 and 2019 are examples. And it will happen again in 2024, 2027, 2030, 2035, and 2038.” {4}
The other rule for determining which spring new moon to use for reckoning Nisan 1 is crop readiness. If the crops in Israel aren’t in a state of “aviv” during the first new moon of spring, then the following new moon would be Nisan 1. Now that the Jews are back in the land of Israel, they should get rid of the calculated Hebrew calendar and go back to an observational calendar. They will need the correct calendar when they build the third temple in Jerusalem during Daniel’s 70th week (especially on the Day of Atonement). Regardless, we know that the Lord Jesus will fulfill the last three Feasts of the Lord on the appointed days as He did during the first four Feasts.
As I mentioned before, the Metonic cycle correlates with the identical Gregorian calendar dates after approximately 6,939 days or 19 years. It’s nearly exact, but the Metonic cycle is 2 hours, 4 minutes, and 58 seconds (or approximately 2.083 hours) longer than 19 tropical years. So, approximately every 218.92 years, the dates will be off by one day. Let’s look at the upcoming year 2025 and go back in time from there. The (first) new moon of spring for 2025 is March 29th. The first new moon of spring for 1816 (twelve 19-year Metonic cycles or 209 years from 2025) is March 28th.
If you went all the way back to the time of Jesus, the date for the first new moon of spring for 30 AD (the first year of Jesus’ ministry) would have been March 20th using the proleptic Gregorian calendar (and the Astro Pixels website). 30 AD is 1995 years (or 105 Metonic cycles) from 2025 AD. There are 2.083 hours of difference between any two Metonic cycles. In this example, there are 105 Metonic cycles, so 105 x 2.083 hours = 218.72 hours. To convert hours into days, we must divide 218.72 hours by 24. This will result in 9.11 days. March 29 (2025 AD) to March 20 (30 AD) is 9 days difference (without reckoning the hours of the new moon conjunctions).
I use AstroPixels – Six Millennium Catalog of Phases of the Moon for reckoning the moon’s phases throughout the millennia. The calendar date changed from Thursday, October 4, 1582 AD (Julian calendar) to Friday, October 15, 1582 AD, when 11 days were added, and the new Gregorian calendar took effect throughout most of the world. For a more accurate reckoning of dates, I use the proleptic Gregorian calendar, which is just extending the Gregorian calendar backward to dates preceding its official introduction.
The date for the vernal equinox in the Northern Hemisphere ranges from March 19 – March 21 on the Gregorian calendar. Every 400 years, going backward or forward, the vernal equinox falls on the same time and date. Example: The time and date for the vernal equinox in 1625, 2025, and 2425 is 9:00 (GMT time) on March 20.
Isn’t it amazing that next year, in 2025, we will be in the same time frame as when Jesus began his earthly ministry? The two spring new moons are nearly identical except for a nine-day difference (out of 1995 years). Could it be we are in the season of the Lord’s return? In the next installment, we will go even further back into the time of Moses and Joshua and look at the timing of the first three Passovers (and the new moons that preceded them) recorded in the Bible.
Until then, “Look up, and lift your heads, because your redemption draws near” (Luke 21:28).
Randy Nettles
Randy Nettles | Profile (rev310.net) – archived articles
Endnotes:
{2} nehemiaswall.com/aviv-barley-in-the-biblical-calendar
{3} Calendar Basics (therefinersfire.org)
{4} The Hebrew Calendar Month (therefinersfire.org)