The Calendar Conversation
Unity in the Midst of Differences
Jeff A. Friedlander

 

As a ministry leader, a Jewish man, and a believer in Yeshua (Jesus) as the Messiah, I hold a deep commitment to the whole counsel of Scripture. I also observe the Biblical holy days and feasts—G-d’s Moadim (appointed times). Year after year, I find that the issue of the biblical calendar remains one of the most common points of confusion and debate, especially among those who are newly engaging with the Hebraic roots of their faith.

Each year, I’m approached by two types of people regarding the calendar. The first group is genuinely hungry to learn. They’ve watched a video, read an article, or heard someone mention an alternate calendar system and want to understand how to align their lives with the Word of G-d. These seekers are often new to walking in the Moadim, and their questions come from a place of wonder and desire for truth.

The second group, unfortunately, often approaches with a different posture. Their questions aren’t rooted in curiosity but in criticism. Rather than seeking wisdom or understanding, they aim to expose perceived error or assert their own correctness. These conversations rarely lead to fruitful outcomes and often stir up division.

Our Approach at Be One

We believe in dialogue, not division. As a community, we refrain from engaging in debates that lead to strife or division. The apostle Paul reminds us in 2 Timothy 2:23:

“Have nothing to do with foolish, ignorant controversies; you know that they breed quarrels.”

Over the years, calendar arguments have proven to be more harmful than helpful, often fracturing communities over details that are important but not ultimately decisive. That said, we are also committed to truth. If G-d reveals that we are walking in error—especially in something as sacred as His appointed times—we are open and willing to change.

Why This Article?

I’ve written this article to provide a balanced overview of the calendar issue—Biblical, historical, and practical. It is not exhaustive, nor dogmatic. It is our current understanding, with room to grow. We believe G-d is still revealing His mysteries (Daniel 12:4), and when He does, we want to be ready to adjust in humility and obedience.

At present, we use the Hillel II calendar—the standard Jewish calendar developed in the 4th century CE—as the basis for calculating months and feasts. While we acknowledge it is not the ancient biblical calendar in full precision, it offers a unified and established method that allows the global community to observe the Moadim together.

 What Is a Biblical Day?

Let’s begin with the foundational passage:

Genesis 1:1–5

In the beginning, God created the heavens and the earth. Now the earth was chaos and waste, darkness was on the surface of the deep, and the Ruach Elohim was hovering upon the surface of the water. Then God said, “Let there be light!” and there was light. God saw that the light was good. So God distinguished the light from the darkness. God called the light “day,” and the darkness He called “night.” So there was evening and there was morning—one day.

From the very first day of creation, we see a key pattern emerge: “There was evening and there was morning—one day.” This phrase appears repeatedly throughout Genesis 1, marking each day of creation.

Interestingly, on that first day, the sun and moon had not yet been created. These celestial lights are not introduced until the fourth day:

Genesis 1:14–19

Then God said, “Let lights in the expanse of the sky be for separating the day from the night. They will be for signs and for seasons and for days and years... the greater light for dominion over the day, and the lesser light... for dominion over the night.” … So there was evening and there was morning—a fourth day.

This tells us something profound: while the sun and moon govern day and night from day four onward, the very concept of day and night—light and darkness—existed even before they were created. On day one, it is G-d Himself who is the source of light (cf. John 1:5; Revelation 21:23). He distinguishes light from darkness and gives the terms "day" and "night" their meaning.

When Does a Biblical Day Begin?

In modern Western thinking, a day begins at midnight. However, the biblical model is different. According to Scripture, the day begins in the evening, not at a time determined by human invention, but by the natural rhythm established in creation. A new day begins when the sun descends, transitioning into darkness, and is later followed by morning light.

This order—evening then morning—is not only theological, but observable. The Hebrew day, still followed in Jewish tradition and biblical calendars, begins at sundown, marked by the fading of sunlight and the first appearance of stars in the sky.

The Gregorian calendar, used globally today, does not reflect this biblical rhythm. Midnight, as the start of a new day, is arbitrary in astronomical terms. There is no physical event that signals midnight in the natural world.

By contrast, the biblical day is aligned with observable events:

  • Evening begins when the sun disappears below the horizon

  • Night deepens as the stars appear

  • Morning arrives with the rising sun

 Time and the Earth’s Rotation

From a scientific perspective, the Earth takes approximately 23 hours, 56 minutes, and 4 seconds to complete one full rotation relative to the stars—this is known as a sidereal day. However, because the Earth is also orbiting the sun, a full solar day (sun returning to the same point in the sky) takes 24 hours. This is the standard by which we measure our days.

So while the scientific measurement of a day helps us track time, it’s the biblical pattern—“there was evening and there was morning”—that gives us the theological framework for understanding how G-d structured time for His creation.

Summary: A Biblical Day

  • Begins in the evening, not at midnight

  • Is marked by observable signs: sun descending and later, sunrise

  • Follows the creation pattern established in Genesis

  • Reflects the sovereignty of G-d over time, not just human calendars

From a Messianic perspective, this rhythm invites us into the shalom and order of G-d’s timing. By aligning our days with His creation rhythm, we reorient our lives around His presence, His Word, and His rest.

What Is a Biblical Week?

The concept of a seven-day week is rooted in the creation narrative. G-d created for six days and rested on the seventh:

Genesis 2:2–3

"By the seventh day God completed His work which He had done, and He rested on the seventh day..." 

The Shabbat (Sabbath) falling on the seventh day, marks the end of the biblical week. Thus, each week is counted from one Shabbat to the next.

G-d has a calendar and special appointments

The Bible gives us clear instructions regarding the measurement of time and the observance of G-d’s appointed times:

Exodus 12:1–2

“The Lord said to Moses and Aaron in Egypt, ‘This month is to be for you the first month, the first month of your year.’”

This declaration by G-d, given just before the Exodus, set a new spiritual calendar in motion for the people of Israel. The month in question—Aviv1 (or Nisan)—would become the first month of the religious year, anchoring the Passover celebration.

Later, in Leviticus 23, G-d outlines His calendar of appointed times:

Leviticus 23:2

“Speak to the people of Israel and say to them, These are the appointed feasts of the Lord that you shall proclaim as holy convocations; they are my appointed feasts.”

These include the weekly Shabbat, as well as the annual feasts: Passover, Unleavened Bread, Firstfruits, Shavuot (Pentecost), Yom Teruah (Trumpets), Yom Kippur (Atonement), and Sukkot (Tabernacles).

To determine the timing of these festivals, Scripture directs us to use the heavenly lights:

Genesis 1:14

“Let there be lights in the expanse of the heavens to separate the day from the night. And let them be for signs and for seasons, and for days and years.”

The Hebrew word for "seasons" here is "moedim"—the same word used for the appointed times. This ties the calendar directly to the sun and moon (Psalm 104:19).

What Is a Biblical Month?

Biblically, months are based on the lunar cycle. A new month begins with the sighting of the new moon, a practice common in ancient Israel and other early civilizations. The ancients typically considered each month to have 30 days.

Historically, cultures like the Hebrews, Babylonians, Egyptians, and Mayans used lunar or lunisolar calendars. While the solar year is approximately 365.24 days, early societies used a 360-day year composed of 12 months of 30 days. Adjustments were later made to account for the difference.

Sir Isaac Newton wrote:

"All nations, before the just length of the solar year was known, reckoned months by the course of the moon... hence came the division of the ecliptic into 360 degrees."2

Biblical Evidence for the use of 30-Day Months

  • The Flood Account: Genesis 7:11 and 8:4 describe a five-month span (from the 17th day of the second month to the 17th day of the seventh month) as lasting 150 days—implying months of 30 days3.

  • Book of Esther: Esther 1:4 mentions a six-month celebration that lasted 180 days.

Prophetic Timeframes:

  • Daniel 7:25 and Revelation 13:5 describe 3.5 years as 1,260 days.

  • Revelation 11:2–3 describes 42 months as 1,260 days, confirming 30-day months.

A Change in Timekeeping

As solar observations advanced, it became clear that the year was closer to 365 days. This led to calendar reforms:

  • Egyptians added five "epagomenal" days to align their 360-day calendar with the solar year4.

  • Babylonians adopted a lunisolar calendar, adding a leap month periodically. Hebrews followed a similar system: 12 lunar months (~29.5 days each = 354 days), with a 13th month (Adar II) added 7 times every 19 years (known as the Metonic cycle).

  • Julius Caesar introduced the Julian calendar, a 365.25-day year with a leap year every four years.

  • Pope Gregory XIII refined it into the Gregorian calendar in 1582, correcting minor drift by adjusting century leap years5.

The First Biblical Month

How Did Ancient Israel Determine the First Month? There were two determinations used to mark the beginning of the new year.

  1. Lunar Cycle:

The new month began with the first visible crescent of the new moon. If the sky was overcast, the month was considered complete after 30 days.

  1. Agricultural Sign (Barley Ripeness – "Aviv"):

The first month (Aviv/Nisan) coincided with the ripening of barley in Israel. The grain had to be ready for the wave offering during Passover (Leviticus 23:10–11). If not, a leap month was added.

Without ripe barley, the festival of Unleavened Bread could not proceed, as the grain was required to make the bread (Exodus 12:15). The Hebrew term "aviv" refers to barley in the green ear stage, ready for harvest.

Post-Temple Era and the Hillel II Calendar

After the destruction of the Second Temple and the dispersion of the Jewish people, it became impractical to rely on barley ripening or new moon declarations. To unify observance:

In 359 C.E., Rabbi Hillel II introduced a fixed lunisolar calendar.

This calendar averages 29.5 days per month and 365.2468 days per year, closely matching the solar year6.

The Hillel II calendar remains the standard for most Jewish and Messianic communities.

The Barley Debate Today

Some groups—such as Karaite Jews, Hebrew Roots Groups, and certain Messianic communities—still conduct barley inspections in Israel to determine the start of the year. These groups often disagree on the timing, resulting in varied dates for the feasts.

However, others have concluded that without a functioning Temple and Levitical priesthood, this practice is no longer available and may not be needed.

Theological Consideration

The Book of Hebrews teaches that the priesthood has shifted from the order of Aaron to the order of Melchizedek, with Yeshua (Jesus) as the High Priest (Hebrews 7). As such, the method, not the principle, of observance has changed: Examples

  • Sacrifices are no longer performed because Yeshua is our final sacrifice.

  • Passover is still remembered, but we no longer slaughter lambs.

  • We observe the feasts as memorials and rehearsals, anticipating Yeshua’s return.

 The Be One Position

At Be One, we utilize the Hillel II calendar, acknowledging its imperfections while valuing its unity and practicality. We acknowledge others’ use of the barley method and respect their convictions, but we do not engage in calendar disputes, as we find them divisive and unproductive.

 Special Note on First Fruits and Shavuot

Two of the appointed times in Scripture—First Fruits and Shavuot (Pentecost)—are unique in that they do not have fixed calendar dates. Instead, their timing is based on counting days in relation to a Sabbath during the week of Passover.

First Fruits

The wave offering of First Fruits is commanded in:

Leviticus 23:10–11

“Speak to the people of Israel and say to them, When you come into the land that I give you and reap its harvest, you shall bring the sheaf of the firstfruits of your harvest to the priest, and he shall wave the sheaf before the Lord, so that you may be accepted. On the day after the Sabbath the priest shall wave it.”

Shavuot (Pentecost)

The command for Shavuot follows just a few verses later:

Leviticus 23:15–16

“You shall count seven full weeks from the day after the Sabbath, from the day that you brought the sheaf of the wave offering. You shall count fifty days to the day after the seventh Sabbath. Then you shall present a grain offering of new grain to the Lord.”

Because these commands are tied to “the day after the Sabbath,” interpretation hinges on which Sabbath the text is referring to. This leads to two primary traditions:

View One: The 6th of Sivan (Rabbinic/Pharisaic Tradition)

In this tradition, the “Sabbath” refers to the first day of Unleavened Bread, which is considered a special Sabbath regardless of the day of the week. Counting begins the next day, the 16th of Nisan, meaning Shavuot will always fall on the 6th of Sivan.

Leviticus 23:6–7

“And on the fifteenth day of the same month is the Feast of Unleavened Bread to the Lord… On the first day you shall have a holy convocation…”

This is the traditional Jewish interpretation, one that has been observed since the Second Temple period, particularly after the destruction of the Temple in 70 CE and the subsequent diaspora. It aligns with the modern Jewish calendar and promotes unity with Jewish communities worldwide.

View Two: The Sunday Resurrection View (Sadducean/Karaite/Messianic Tradition)

In this view, the “Sabbath” is interpreted as the weekly Sabbath (Saturday) that falls during the week of Unleavened Bread. Therefore, the wave offering of First Fruits is always observed on a Sunday, and counting begins from that Sunday—making Shavuot always fall on a Sunday.

This was the practice of the Sadducees, Zadokites, and likely the Qumran community, reflecting early Temple-era observance. It also corresponds with the resurrection of Yeshua (Jesus), which occurred on a Sunday—making that year’s First Fruits and Shavuot fall on Sundays, further reinforcing the typology between the Messiah and the Feasts.

Why Both Views Matter

Each interpretation has compelling reasons:

Sunday View

  1. Aligns First Fruits with the resurrection of Yeshua, our risen Messiah.

  2. Matches the calendar pattern in the year of Yeshua’s death and resurrection.

  3. Reflects the likely practice of the pre-Pharisaic Temple period.

6th of Sivan View

  1. Supported by Second Temple Pharisaic tradition and still used in modern Judaism.

  2. Promotes calendar unity with the wider Jewish world.

  3. Provides continuity across centuries of Jewish heritage and tradition.

Our Approach at Be One

Because both interpretations are Scripturally plausible and historically grounded, Be One Fellowship has chosen to follow the Hillel II calendar, the traditional Jewish calendar in use since the 4th century CE. This approach keeps us aligned with the global Jewish community and honors our connection to both Jewish history and heritage.

Our leadership continues to evaluate the calendar with prayer and discernment. We remain open to revisiting this matter in the future, seeking above all to be Biblical, unifying, and pleasing to the Lord in our observance.

Regardless of the specific day, our heart is to honor G-d and His appointed times with joy, reverence, and unity. As Paul reminded us in Colossians 2:17, these feasts are a shadow of things to come—but the substance belongs to Messiah.

Conclusion

The Biblical calendar teaches us to observe time as G-d intended: with rhythms rooted in creation, agriculture, and celestial signs. While methods of reckoning time have changed, the heart of Biblical observance remains to honor G-d, remember His works, and anticipate the fulfillment of His promises.

 

 Footnotes

  1. Aviv is the Hebrew name for the first month of the year. After the exile to Babylon, the name Nisan was added.

  2. Sidereal time measures Earth's rotation relative to distant stars. A sidereal day is about 23h 56m 4s.

  3. Anderson, Robert. The Coming Prince. London: Hodder & Stoughton, 1894.

  4. Genesis 7:11, 24 and 8:3–4 document a five-month period as 150 days, implying 30-day months.

  5. Epagomenal days are added to solar calendars to account for the ~5.25-day gap beyond a 360-day year.

  6. The Gregorian reform skips leap years on century years not divisible by 400.