Biblical Calendar
And God (Elohim) 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.
Genesis 1:14
Understanding Biblical or Hebrew calendar is essential for comprehending biblical narratives, prophecies, and concepts. The calendar establishes timelines for God's festivals like Passover and the Feast of Tabernacles. It serves as a key to prophetic timelines, allowing us to better understand biblical prophecies and their relevance to current and future events. The cultural context of the calendar, which includes seasonal cycles and agricultural practices, can aid in the interpretation of metaphors in biblical prophecies like the harvest at the end of the age in Revelation 14:14-15. Finally, its seven- and fifty-year cycles underline the concepts of sabbatical and jubilee years, which point to the Messianic hope and the ultimate fulfilment of God's plan in the New Covenant.
Biblical Calendar Structure
Biblical calendar is a lunisolar system based on the natural cycles of the sun and moon, with months based on lunar months and years based on solar years.
Day
In the biblical calendar, a day starts at sunset and ends at the following sunset. This concept comes from the creation narrative in Genesis, where each day begins with the phrase "And there was evening, and there was morning, the [nth] day."
5 God called the light “day,” and the darkness He called “night.” And there was evening, and there was morning—the first day.
Week
1 2 3 4 5 6 7
The week spans seven days, mirroring the seven days of creation as depicted in Genesis 1 and 2. Day one of creation begins with the separation of light from darkness, and the week culminates with the completion of creation and God's rest on the seventh day. This seventh day, known as the Sabbath, is observed from sunset on Friday to sunset on Saturday, in accordance with the commandment to remember the Sabbath day and keep it holy (Exodus 20:8).
3 And God said, “Let there be light,”a and there was light. 4 And God saw that the light was good, and He separated the light from the darkness. 5 God called the light “day,” and the darkness He called “night.” And there was evening, and there was morning—the first day.
6 And God said, “Let there be an expanse between the waters, to separate the waters from the waters.” 7 So God made the expanse and separated the waters beneath it from the waters above. And it was so. 8 God called the expanse “sky.” And there was evening, and there was morning—the second day.
9 And God said, “Let the waters under the sky be gathered into one place, so that the dry land may appear.” And it was so. 10 God called the dry land “earth,” and the gathering of waters He called “seas.” And God saw that it was good. 11 Then God said, “Let the earth bring forth vegetation: seed-bearing plants and fruit trees, each bearing fruit with seed according to its kind.” And it was so. 12 The earth produced vegetation: seed-bearing plants according to their kinds and trees bearing fruit with seed according to their kinds. And God saw that it was good. 13 And there was evening, and there was morning—the third day.
14 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. 15 And let them serve as lights in the expanse of the sky to shine upon the earth.” And it was so. 16 God made two great lights: the greater light to rule the day and the lesser light to rule the night. And He made the stars as well. 17 God set these lights in the expanse of the sky to shine upon the earth, 18 to preside over the day and the night, and to separate the light from the darkness. And God saw that it was good. 19 And there was evening, and there was morning—the fourth day.
20 And God said, “Let the waters teem with living creatures, and let birds fly above the earth in the open expanse of the sky.” 21 So God created the great sea creatures and every living thing that moves, with which the waters teemed according to their kinds, and every bird of flight after its kind. And God saw that it was good. 22 Then God blessed them and said, “Be fruitful and multiply and fill the waters of the seas, and let birds multiply on the earth.” 23 And there was evening, and there was morning—the fifth day.
24 And God said, “Let the earth bring forth living creatures according to their kinds: livestock, land crawlers, and beasts of the earth according to their kinds.” And it was so. 25 God made the beasts of the earth according to their kinds, the livestock according to their kinds, and everything that crawls upon the earth according to its kind. And God saw that it was good. 26 Then God said, “Let Us make man in Our image, after Our likeness, to rule over the fish of the sea and the birds of the air, over the livestock, and over all the earth itself and every creature that crawls upon it.” 27 So God created man in His own image; in the image of God He created him; male and female He created them...31 And God looked upon all that He had made, and indeed, it was very good. And there was evening, and there was morning—the sixth day.
2 And by the seventh day God had finished the work He had been doing; so on that day He rested from all His work. 3 Then God blessed the seventh day and sanctified it, because on that day He rested from all the work of creation that He had accomplished.
Month
The biblical calendar follows a lunar cycle, beginning each month with the sighting of the new moon. In Hebrew, the word for month is חֹדֶשׁ (chodesh), derived from the root חָדַשׁ (chadash), meaning new. According to God's Law, the start of each month was marked by the blowing of trumpets and the offering of burnt sacrifices. This commandment is prophesied to be observed again during the Millennial Kingdom, as foretold in the book of Isaiah.
10 And on your joyous occasions, your appointed feasts, and the beginning of each month, you are to blow the trumpets over your burnt offerings and fellowship offerings to serve as a reminder for you before your God. I am Yahweh your God.”
11 At the beginning of every month, you are to present to Yahweh a burnt offering of two young bulls, one ram, and seven male lambs a year old, all unblemished, 12 along with three-tenths of an ephah of fine flour mixed with oil as a grain offering with each bull, two-tenths of an ephah of fine flour mixed with oil as a grain offering with the ram, 13 and a tenth of an ephah of fine flour mixed with oil as a grain offering with each lamb. This is a burnt offering, a pleasing aroma, an offering made by fire to Yahweh.
23 From one New Moon to another and from one Sabbath to another, all mankind will come to worship before Me,” says Yahweh.
Biblical Months
Most biblical months were given enumerations instead of names. Akkadian names for the equivalent lunar months in the Babylonian lunisolar calendar came to be applied to the Jewish calendar during the Babylonian captivity.
Passover (Nisan 14), Unleavened Bread (Nisan 15-22), Firstfruits (Sunday during Nisan 15-22)
The Hebrew word "Aviv" means "barley ripening" or "spring season". In Akkadian, the month of Aviv is called "Nisan". Its original name was Araḫ Nisānu, which means "month of beginning." Although the month's name is derived from the Akkadian language, it originates from Sumerian nisag, which means "first fruits".
"This month shall be for you the beginning of months. It shall be the first month of the year for you."
"Today, in the month of Abib, you are leaving. And when Yahweh brings you into the land of the Canaanites, Hittites, Amorites, Hivites, and Jebusites—the land He swore to your fathers that He would give you, a land flowing with milk and honey—you shall keep this service in this month.
"In the twelfth year of King Xerxes, in the first month, the month of Nisan, the Pur (that is, the lot) was cast before Haman to determine a day and month. And the lot fell on the twelfth month, the month of Adar.
Before the Babylonian captivity, the month was called Ziv, meaning "light" or "glow" in Hebrew. The name Iyar was given during the Babylonian captivity. In the Babylonian calendar, it was called Araḫ Āru, meaning "month of blossoming".
In the four hundred and eightieth year after the Israelites had come out of the land of Egypt, in the month of Ziv, the second month of the fourth year of Solomon’s reign over Israel, he began to build the house of Yahweh.
The foundation of the house of Yahweh was laid in the fourth year of Solomon’s reign, in the month of Ziv.
The name Sivan is derived from Akkadian simānu, which means "season or time". In the Babylonian calendar, it was named Araḫ Simanu.
At once the royal scribes were summoned, and on the twenty-third day of the third month, the month of Sivan, they recorded all of Mordecai’s orders to the Jews and to the satraps, governors, and princes of the 127 provinces from India to Cush —writing to each province in its own script, to every people in their own language, and to the Jews in their own script and language.
The month of Tammuz was named after the Assyrian and Babylonian month Araḫ Dumuzu, honoring the Mesopotamian deity Dumuzid or Tammuz, known to the Sumerians as Dumuzid the Shepherd.
And on the ninth day of the fourth month of Zedekiah’s eleventh year, the city was breached.
“This is what Yahweh of Hosts says: The fasts of the fourth, the fifth, the seventh, and the tenth months will become times of joy and gladness, cheerful feasts for the house of Judah. Therefore you are to love both truth and peace.”
The name Abu appears on the Babylonian calendar and is derived from Akkadian ʾAbū, which may mean "reed" or be related to the name of the Mesopotamian god Abu. Others attribute the month's name to the Hebrew word "Av" meaning "father" or the corresponding Akkadian word "abum". In the Levant, August is known as Ab in Arabic.
At Yahweh’s command, Aaron the priest climbed Mount Hor and died there on the first day of the fifth month, in the fortieth year after the Israelites had come out of the land of Egypt.
Now the people of Bethel had sent Sharezer and Regem-melech, along with their men,b to plead before Yahweh by asking the priests of the house of Yahweh of Hosts, as well as the prophets, “Should I weep and fast in the fifth month, as I have done these many years?”
The name Elul is comes from Akkadian word Elūlu meaning "harvest". In the Babylonian calendar, the month is referred to as Araḫ Ulūlu "harvest month".
So the wall was completed in fifty-two days, on the twenty-fifth of Elul.
Trumpets (Tishrei 1), Day of Atonement (Tishrei 10), Tabernacles (Tishrei 15-22)
The name Tishrei is derived from Akkadian tašrītu "beginning" and šurrû "to begin". In the Babylonian calendar, the month is known as Araḫ Tišritum, which means "Month of Beginning". It is the first month of the civil year and the seventh month of the ecclesiastical year on the Hebrew calendar. The month is known as Ethanim in Hebrew, which means "steady flowings".
"Speak to the people of Israel, saying, 'In the seventh month, on the first day of the month, you shall observe a day of solemn rest, a memorial proclaimed with blast of trumpets, a holy convocation.'"
And all the men of Israel came together to King Solomon at the feast in the seventh month, the month of Ethanim.
The name Marcheshvan, or shortened version Cheshvan, comes from Akkadian waraḫsamnu, which literally means "eighth month".
In his eleventh year and eighth month, the month of Bul, the temple was finished in every detail and according to every specification. So he built the temple in seven years.
Hanukkah or Feast of Dedication
The name of the month Kislev comes from the Akkadian word kislimu. In the Babylonian calendar, it was called Araḫ Kislimu. Some etymologies link it to the Hebrew root K-S-L, as in the words "kesel, kisla" (hope, positiveness) or "ksil" (Orion, a constellation that shines especially during this month) referring to the expectation and hope for rain. Even though the name Kislev does not appear in the Bible, it can be found in the Apocryphal book of Maccabees.
So within the three days, all the men of Judah and Benjamin assembled in Jerusalem, and on the twentieth day of the ninth month, all the people sat in the square at the house of God, trembling regarding this matter and because of the heavy rain.
"At that time the Feast of Dedication took place at Jerusalem. It was winter."
"Now the fifteenth day of the month Kislev, in the hundred forty and fifth year, they set up the abomination of desolation upon the altar, and builded idol altars throughout the cities of Judah on every side."
Tevet was known as Araḫ Ṭebētum, or the "muddy month" in the Babylonian calendar.
"And in the ninth year of his reign, in the tenth month, on the tenth day of the month, Nebuchadnezzar king of Babylon came with all his army against Jerusalem and laid siege to it. And they built siege works all around it."
She was taken to King Xerxes in the royal palace in the tenth month, the month of Tevet, in the seventh year of his reign.
The Akkadian origin of the month Shevat is Šabātu, which means strike and refers to the heavy rains of the season.
On the twenty-fourth day of the eleventh month, the month of Shebat, in the second year of Darius, the word of Yahweh came to the prophet Zechariah son of Berechiah, the son of Iddo.
In the Babylonian calendar, the month was called Araḫ Addaru or Adār.
In the twelfth year of King Xerxes, in the first month, the month of Nisan, the Pur (that is, the lot) was cast before Haman to determine a day and month. And the lot fell on the twelfth month, the month of Adar.
Biblical Year
The biblical year is comprised of either 12 or 13 lunar months, resulting in a lunar-solar calendar. To align the lunar calendar with the solar year, an additional month, known as Adar II, is added in certain years to ensure that festivals and agricultural practices align with the correct seasons. This adjustment is necessary because the lunar year is around 11 days shorter than the solar year.
In the Biblical calendar, a year can vary in length, ranging from 353 to 385 days.
A typical year consists of 12 months, or 354 days. However, leap years deviate from this pattern, lasting 13 months and 384 days. Odd-numbered months typically have 30 days, whereas even-numbered months have 29 days.
Biblical new year begins on Nisan 1, which has to coincide with the sighting of the new moon and the ripeness of barley to ensures the that it is ready for the firstfruits offering.
In civil contexts, Rosh Hashana, which falls on Tishrei 1, marks the start of a new year on the Jewish calendar.
When Was Year 1?
The Biblical year count starts in year 3761 BCE, which the 12th-century Jewish philosopher Maimonides established as the biblical Date of Creation.
Years in the Jewish calendar are designated AM to identify them as part of the Anno Mundi epoch, indicating the age of the world according to the Bible. For example, the beginning of the year 2021 in the Gregorian calendar converts to year AM 5781 in the Biblical calendar.
Leap Year Rules
In the Jewish calendar months are based on the phases of the Moon. Each month begins with the appearance of a Crescent Moon after the New Moon phase and lasts for a full Moon cycle.
Since the sum of 12 lunar months is about 11 days shorter than a solar year, a leap month is added every 2 to 3 years, or 7 times in a 19-year cycle. Leap months are meant to keep the calendar in step with the astronomical seasons and make sure that the religious observances occur at the correct time of year, as mentioned in the Bible.
History and Background
The Biblical calendar is based on a history of time keeping efforts dating back to ancient times. Both Israelite and Babylonian influences played an important role in its development. According to the account of Persian astronomer al-Khwarizmi (c.780–850 CE), most of the features of its modern-day version were in place by the 9th century CE.
The timing of the months in the early forms of the Jewish calendar depended on actual sightings of the Crescent Moon. However, this practice was gradually changed, and by 1178 CE the calculation of the beginning of a new calendar month had been fully replaced by the mathematical approximation of the moment the Crescent Moon begins to appear (Molad) rather than actual sightings.