The final variable we must nail down is identifying which month starts the year. There are a number of different proposals out there, but before getting to the proposals we must start with the principles and then test each of the proposals against it.

We have already established that the Sun, Moon, and stars are for days and years. We have also put forth the principle that everyone, everywhere, without reliance upon a subjective central authority, or impractically difficult manual mathematics, should be able to observe and obey God's commands. The reason for this is because scripture says "they not too difficult for you". Scripture adds one additional constraint or principle that applies to the places the start of the year in the spring:

This month shall be unto you the beginning of months: it shall be the first month of the year to you.

— Exodus 12:2

This command comes directly from God to Moses and Aaron in the context of the first Passover and the Exodus from Egypt. The month in view is Abib (later called Nisan), the spring month when Passover occurs. This establishes Nisan (spring) as the starting point for the religious/sacred calendar—the counting of months for festivals, feasts, and redemptive events (e.g., Leviticus 23 frequently refers to "the first month" for Passover/Unleavened Bread).

Other verses reinforce this primacy of the spring new year for religious purposes:

This day came ye out in the month Abib.

— Exodus 13:4

In the first month, on the fourteenth day of the month at even, is the LORD's passover.

— Leviticus 23:5

The name Abib/Aviv is not arbitrary; it describes a precise stage of barley ripeness essential to the divine calendar. Exodus reveals this during the plague of hail:

And the flax and the barley was smitten: for the barley was in the ear [abib/aviv], and the flax was bolled.

— Exodus 9:31

Here, "in the ear" (aviv) indicates barley that has formed heads—mature enough to be destroyed by hail, yet not fully ripe and dry. This stage ensures the crop is brittle and vulnerable but still standing with kernels developing inside.

This matters for Passover timing because the first month must begin such that barley reaches harvest-readiness by the wave-sheaf offering (first fruits) on the 16th of the month.

Seven weeks shalt thou number unto thee: from such time as thou begin to put the sickle to the standing corn [grain] shalt thou begin to number seven weeks.

— Deuteronomy 16:9

The sickle begins on the standing barley during Passover week—typically 15–21 days after the month's start—so the month opens when barley is aviv (in the ear, heading, soft dough stage), ensuring it ripens fully by First Fruits without rotting in the field from over-maturity. If barley were already overripe at month's start, the harvest would begin too early, spoiling the appointed timing; if too green, it could not mature in time for the omer offering.

The ripening season for barley—from the point when the first heads reach harvest-readiness to when the last heads in a field are fully ripe and ready for harvest (physiological maturity, hard kernels, low moisture)—typically spans 2 to 4 weeks, depending on variety, weather, and field conditions.

Lunar years do not perfectly align with solar years and the barely harvest is largely determined by the solar climate. This means that there can be up to 29 days shift in the start of the lunar year which happens to be near the upper limit of the barley harvest tolerance.

The barley ripening season in ancient Israel (particularly in the warmer Jordan Valley and lowlands, where the earliest crops matured) generally began around 2–4 weeks after the vernal (spring) equinox (typically March 20–21 in the Gregorian calendar).

First ripe barley ("aviv" stage): The earliest heads reach the aviv stage (young ears in the head, soft dough/milky, harvest-ready for the wave sheaf) often around late March to early April, or roughly 7–26 days after the equinox. Historical and modern observations (e.g., from 19th–20th century reports and contemporary Israeli agricultural data) place the start of harvest in the Jordan Valley/Jericho area as early as end of March (about 10–20 days post-equinox in average years), with some variability due to weather which generally postpones it.

General field ripening: Full harvest readiness across a region (from first to last heads) spreads over 2–4 weeks, as microclimates, elevation, and varieties cause staggered maturity. In the Jordan Valley (lowest/warmest), it could start 1–2 weeks earlier than in the hills around Jerusalem.

The equinox marks the astronomical start of spring, and barley's growth is solar-driven. Aviv barley needed to be present at the month's beginning (new moon) so it could ripen in time for the wave sheaf ~15–21 days later (during Unleavened Bread). Biblical and historical sources ensure the first month opens such that harvest aligns post-equinox without over-maturity/rot (barley spoils quickly once fully ripe).

Because we have a principle that everyone, everywhere must be able to discern the seasons, we cannot rely upon direct subjective observation of the state of the barley harvest to determine when the year starts because barley timing is largely location dependent and in many places you cannot even grow barley. Instead we use the barley as evidence of what kind of celestial events to look at.

The Spring Equinox

The most common sign that people use, one way or another, is the Spring Equinox which is the day when the sun rises due East and sets due West and at noon is directly overhead. At this time there is about 12 hours of daylight and 12 hours of darkness.

Jesus once asked his disciples a simple yet profound question in the midst of rising danger:

Are there not twelve hours in the day? If anyone walks in the day, he does not stumble, because he sees the light of this world.

— John 11:9

This wasn't casual small talk about the weather or the length of daylight. It was a deliberate revelation of timing, purpose, and alignment with divine order. When Jesus spoke of exactly twelve hours, he pointed to a moment of perfect balance—when day and night divide equally. This occurs at the spring equinox, the turning point when light begins to overcome darkness in the northern hemisphere. In the land of Israel, around latitude 31°N, this balance happens near March 20–22 in our modern reckoning.

Now consider the biblical calendar, which isn't arbitrary or man-made in the way modern civil calendars are. The year begins with Nisan—the month of Aviv—tied directly to the ripening of barley and synchronized with the spring season. The renewed moon that starts Nisan is the one closest to or following the spring equinox, ensuring Passover falls in spring, when renewal and liberation are manifest in nature itself. The equinox marks the tekufah, the seasonal turning described in Scripture (Exodus 34:22), a natural turning point that aligns solar cycles with lunar months to keep the feasts in their appointed times.

The events surrounding Jesus' words in John 11 unfold just before Passover. He had delayed going to Judea despite the threat to his life, then declared it was time to go—because the "day" had its appointed hours, and he was walking in the light of his Father's will. After raising Lazarus, John 11:55 notes that "the Passover of the Jews was at hand," with many people already traveling to Jerusalem to purify themselves. Then, John explicitly states:

Six days before the Passover, Jesus came to Bethany, where Lazarus was, whom Jesus had raised from the dead.

— John 12:1

The following table is the minimum reconstructed timeline given the available information. It shows that the latest possible day for Jesus to say "are there not 12 hours in a day" is the 4th of the first month; however, if the stay in Ephraim was longer than one day then it could easily push the "12 hours in a day" comment to Renewed Moon day on the first day of the month. In this context Yeshua's question could rhetorically be stating the precondition for the year starting.

Day	Event
14th	Passover
10th	Triumphant Entry
9th	Jesus came to back Bethany (15 miles), 6 days to Passover
8th	Sabbath (assuming Lunar Sabbath, no narrative points here)
7th	Jesus walks to Ephraim (15 miles)
6th	Jesus raises Lazarus on 4th day
5th	Jesus travels to Lazarus (20+ miles)
4th	Second Day Jesus Waits, says "are there not 12 hours"
3rd	First Day Jesus Waits, Lazarus Dies
2nd	Jesus receives message
1st	Renewed Moon Day (message about Lazarus' sickness sent)

Whether or not this was his intention, the fact remains that if the year were to start before the Spring Equinox then the barely would be unlikely to be ready. Bad weather conditions such as being cold and wet can delay Barley, but good weather conditions cannot easily accelerate it.

Feast of Ingathering

You shall observe the Feast of Weeks… and the Feast of Ingathering at the turning (tekufah) of the year.

— Exodus 34:22

The Feast of the Ingathering is a name for the feast of Tabernacles which is the 15th of the 7th month. Many scholars connect tekufah with the equinox as one of the turning points in the calendar. If the Feast of Ingathering is at one turning point, then it stands that Passover should be near the other.

Traditional Start of Year

The traditional calculated Jewish calendar (established by Hillel II in the 4th century CE and still in use today) does not always place Nisan 1 after the vernal equinox. While its primary goal is to ensure Passover (Nisan 15) falls in spring—typically after the equinox—through a combination of intercalation (adding Adar II in leap years on a 19-year Metonic cycle) and postponement rules (deḥiyyot for Rosh Hashanah/Tishrei 1), these mechanisms prioritize seasonal alignment for the feasts rather than strictly fixing Nisan 1 post-equinox.

The calendar relies on calculating the equinox (along with the molad/new moon conjunction and weekday rules) weeks in advance to decide intercalations and postponements. This means that about 1 in 5 years they start the year so early that the Barley is unlikely to be ripe by first fruits.

A particularly notable year where this happens is 33 AD. The second most popular date of the cross, April 3rd, 33 AD depends upon assuming a calendar that starts the month several days before the equinox. A result only possible by calculation and if your calendar is indifferent to the need for barely ripeness. When you add the necessary postponement, Passover in 33 AD falls on Saturday using the "visible crescent" calendar.

Spica

Some people put forth the idea that "Aviv" is a reference to the "barley seed" in the hand of the constellation virgo. They then use the metric that the Renewed Moon (full moon) should set after the star Spica. In recent centuries this approach can align with using the first full moon after the equinox on many years, but some years it falls a month later. If you go back 2000 years then the two align more frequently, but if you go back 4000 years then this calendar comes in too early relative to the equinox.

The precession of the equinoxes is a slow, cyclical wobble in Earth's axial tilt, akin to a spinning top gradually shifting its orientation, caused by gravitational pulls from the Sun and Moon on Earth's equatorial bulge. This precession completes a full cycle every approximately 25,772 years, causing the position of the vernal equinox (where the Sun crosses the celestial equator) to drift westward along the ecliptic by about 50 arcseconds per year relative to the fixed background stars. As a result, the zodiac constellations that align with the equinoxes and solstices slowly shift over millennia—what was once Aries at the spring equinox in ancient times is now Pisces, and will eventually become Aquarius.

Linking the start of the year to any fixed stellar reference, such as the Sun or Moon's position relative to a star like Spica in Virgo (the "barley seed" in some interpretations), inevitably leads to seasonal drift over thousands of years because these alignments are sidereal (star-based) and ignore precession's gradual realignment of Earth's seasons with the zodiac. A calendar tied to such a star will initially sync with solar seasons but slip backward by about one zodiac sign every 2,000 years—too early relative to the equinox 4,000 years ago, occasionally aligning 2,000 years ago, and lagging a month later in recent centuries. This drift disrupts harmony with the land's rhythms, as feasts wander from spring renewal to winter chill.

For these reasons it fails to meet one of the principles outlined for the start of the year.

Conclusion

To ensure the year starts with ripe Barley on Aviv 16th requires the use of the first renewed moon after the equinox. Even 2 weeks earlier would cause some years to lack ripe Barley. Any additional delay and the barley harvest would be entirely over in some years.

And God said, "Let there be lights in the expanse of the sky to distinguish between the day and the night, and let them be signs to mark the seasons and days and years. And let them serve as lights in the expanse of the sky to shine upon the earth." And it was so.

— Genesis 1:14