It's About Time: A Guide to the Jewish Calendar

Jews are a little obsessed with time.

This obsession began at the very start of our story. The Bible doesn’t open with people, nations, or laws — but with the foundation of time itself: One day was created. That worked well, so God kept going. Our next great literary creation, the Talmud, also opens with a question about time: Until what time may a person recite the evening Shema prayer? The fixation doesn’t end there. Jewish law prescribes precise moments for prayer and rest; our religion sanctifies recurring cycles of days, weeks, and seasons; and our historical consciousness is shaped by anniversaries, memorial dates, and commands to remember the past at specific times.  All of this is expressed practically in the Jewish calendar — the system that structures Jewish days, weeks, months, years, and holidays.

So why are Jews so focused on time — and how does the Jewish calendar actually work?

If you’ve ever wondered why Israel shuts down on Friday afternoon, why Jewish holidays “move around” on your calendar, or why Shabbat seems to arrive early and leave late, this guide to the Jewish calendar is for you. 

The Jewish Day: Sunset to Sunset

Sunset in Mitzpe Ramon, Israel — the start of a new day in the Jewish calendar. Photo: Johannes Schenk

The most noticeable difference between the way Jews and non-Jews experience time is how we measure our days.

The Jewish day starts and ends at sunset. The source for this is the first book of the Torah, called Bereshit in Hebrew and Genesis in English.

“God called the light Day and called the darkness Night. And there was evening, and there was morning — one day.” — Genesis 1:5

Because evening is mentioned before morning in this sacred text, the Jewish day is counted from sunset to sunset. 

This is especially important on Shabbat, our weekly day of rest. Shabbat begins on Friday at sunset, when the mother of a household lights the Shabbat candles, and lasts until Saturday night, when three stars can be seen in the sky. Understanding Shabbat timing is clutch for both Jews and non-Jews with Jewish friends. Why? 

If you’re invited to Shabbat dinner and you accidentally show up on Saturday night, you’ll end up eating leftovers!

The Jewish Week: Building Toward Shabbat

My Shabbat dinner table

In Hebrew, the days of the week aren’t named after gods or planets. The six workdays of the week are simply called the first day (Yom Rishon), the second day (Yom Sheni), and so on — all leading toward Shabbat, our week’s designated rest day and the only day of the week with a unique name.

The structure of the Jewish week mirrors the biblical creation story: The world was formed in six days before God rested on the seventh.

The texts chiseled into these shabti figurines displayed in the Louvre indicate that they will perform work for their owners in the afterlife.

But Shabbat isn’t just a religious concept. It’s also a social one.

According to Jewish tradition, while enslaved in Egypt, Jews suffered under a rigid social hierarchy in which rest was a privilege of the elite. This changed when, as recorded in Shemot Rabbah, Moses convinced Pharaoh that all strata of society benefit from taking one day off from work each week.

Shabbat introduced a radical notion: Everyone gets to rest — masters, servants, and even animals. This highly democratic idea was revolutionary — and particularly cherished by slaves.

Interestingly, Egyptians buried their dead with finger-sized figurines called “shabti,” which were meant to labor for them in the afterlife so the dead could rest eternally. The Hebrew Bible, written by people exposed to this culture, may have adopted the Egyptian word for our weekly day of rest.

Jewish Months

Jewish months follow the moon. Each month begins with the appearance of the moon’s crescent. 

In Hebrew, the moon is commonly called the yareach. In Classical Hebrew, the very similar word yerach was occasionally used as a poetic word for “month,” as is seen in Exodus 2:2, when an infant Moses was hidden by his mother for the first three yerachim of his life to escape Pharaoh’s infanticidal decree. The more common word for month, however, is chodesh, from chadash, meaning “new.”

Jewish months last 29 or 30 days — the time it takes for a lunar cycle to complete. Originally, the first month of the Jewish year was Nisan, in the spring. In ancient times, Jews were shepherds, and spring lambing season was critical.

Later, when Jews became farmers, priorities shifted. The agricultural year begins in autumn, and the Jewish calendar’s first month shifted accordingly to the autumn month of Tishrei.

The moon over the Kinneret (Sea of Galilee) near Capernaum (Kfar Nahum) National Park in Israel. Photo: JR Ross

Jewish Years

Refill your plate of rugelach, because this is where things get complicated. 

When Jews were shepherds, we relied on moonlight to help us keep an eye on our herds at night. When we became farmers, the moon became less significant than the sun, which sets the seasons.

In true Jewish fashion, we mixed a bit of the old and a bit of the new, creating a lunisolar calendar. Our months are lunar, but our years are solar.

This approach isn’t without its challenges. A lunar year is about 354 days; a solar year is about 365. And those missing 11 days need to be accounted for.

That gave Jewish scholars the thing they liked most: a problem to solve.

Jewish leap year

There’s an early springtime month in the Jewish calendar called Adar. And every two to three years, Jews observe an extra month in the spring called Adar Bet — the second month of Adar. 

The math works out so that in a 19-year cycle of the Jewish calendar, seven years are 13-month leap years. This system, innovated in the fourth century by Rabbi Hillel Nesia, has kept — and will keep — the Jewish calendar aligned for thousands of years.

The Christian world took notice.

Jewish calendar vs Gregorian calendar

Early Christian Europe, an agricultural society, used a fully solar calendar, named the Julian calendar after its creator, Julius Caesar. A solar year has 365 days and a quarter.

This extra quarter day was balanced every four years by adding an extra day in February, the 29th. But this system wasn't very accurate. And after 1,600 years of the Julian calendar, Christian scholars noticed a problem. Easter was supposed to align with the springtime Jewish holiday of Passover (Pesach in Hebrew), when Christians believe the crucifixion of Jesus took place. Instead, it was gradually drifting toward summer.

Inspired by the Jewish calendar, Pope Gregory XIII introduced the Gregorian calendar, refining leap years and correcting accumulated error by simply removing days from the calendar.*

Other cultures have taken different approaches.

The Islamic calendar, designed for a pastoral society, is fully lunar, which explains why Muslim months like Ramadan may be observed in completely different seasons, depending on the year. And the annual 11-day lunar-solar gap adds up to one missing year every 33 years. 

So, the next time you meet a Muslim who tells you they’re 33, you can compliment them by noting that they’re only 32, Islamically speaking.

Shmita

Another Jewish calendar quirk is that, in addition to our weekly rest day, we have a periodic rest year.

Every seven years, many Israeli farmers observe shmita, a biblical sabbatical year for the land. Traditionally, crops aren’t planted or harvested during shmita years, and any food that grows is given to the poor.

This was feasible for a 4th-century family-run farm with two acres and four fruit trees to its name; it’s less realistic for 21st-century industrialized agriculture, bound by loans, export contracts, and dozens of laborers.

But there’s a workaround: During shmita years, Israeli farmers temporarily sell their land to a court (heiter mechira), changing their status from owners to tenants of the land and allowing them to continue cultivating it without violating the commandment.

Jewish Holidays: The Rhythm of Agriculture

The Jewish experience of time is inseparable from the land we inhabit. Our roots as farmers and herders shaped not only how we worked the land of Eretz Israel, but also how we measured the passing months and years.

And nowhere is that heritage more clearly sanctified than in the cycle of Jewish holidays, which express our agricultural and pastoral origins in surprising ways.

High Holidays = plowing, seeding, and harvesting

Apples, traditionally harvested in late summer and early autumn in Israel, are eaten with honey on Rosh HaShanah to ensure the coming year will be sweet. Photo: Olga Drach

The year begins with the first autumn plowing. That’s when Rosh HaShanah, our new year holiday, is celebrated on the first two days of the month of Tishrei, which usually corresponds to a September date in the Gregorian calendar.

Farmers then seed their fields following a 10-day interval called the Days of Awe. It’s a period of contemplation and uncertainty — in biblical times, a farmer couldn’t predict if the year ahead would be abundant or if his family would starve. The Days of Awe conclude with Yom Kippur, the Day of Atonement, on the 10th of Tishrei, when Jews fast and reflect on their deeds of the preceding year. 

A few days later, the farmer gathers fruits and vegetables from his fields and orchards. It’s all ripe, and he doesn’t want it to be stolen, so he builds an outdoor hut (sukkah in Hebrew) and starts collecting the produce. This period is marked by the festival Sukkot (15–21 Tishrei) when contemporary observant Jews — urban and rural alike — build a sukkah and sleep in it for seven days. 

This is the time when, during morning prayers (Shacharit), Jews pray for rain. Even Jews in exceedingly rainy places, like Vancouver, will pray for rain while being drenched in their sukkah. Doesn't make sense, does it? Actually, it makes perfect sense. Because this Jew in Vancouver isn't praying for rain where he is — he's praying that it will rain for farmers in Israel. These rain prayers continue for six months — after six months, we start praying for dew.

After the farmer finishes his harvest and has enough food to feed his family for the next year, he can finally celebrate. The end of Sukkot is accordingly marked by Simchat Torah on 23 Tishrei, or “the Joy of Torah” in Hebrew, when we rejoice and dance with the Torah scrolls in the synagogue.

Hanukkah follows the olive harvest

My Hanukkah menorah on Hanukkah's fifth night. Oil from the olive harvest is traditionally used to light the Hanukkah menorah.

Then comes the time to gather one of Israel’s most important crops: olives. Olive oil was the main source of fat in ancient Israel and was used to illuminate Jewish homes and the Temple in Jerusalem.

Picking and pressing olives is hard work, so the months of Cheshvan and Kislev (October/November/December) are busy. Once olive season is over, we celebrate Hanukkah (25 Kislev–2 Tevet), the eight-day Festival of Lights, by lighting a special candelabrum and making fried treats like blintzes, latkes, and doughnuts from the surplus harvest oil. It's the holiday of weight-gain.

Nothing major happens for the rest of Tevet (December/January) — it’s all rain and mud, creating wet and deep soil ideal for planting new trees.

Planting trees and putting on costumes

Things pick up again on the holiday Tu B’Shvat, the 15th day of Shvat (January/February), when Israeli children plant trees.

One month later, spring sunshine and blossoms arrive during the month of Adar (February/March). The uplifting weather sets the mood for a carnival with masks, wine, and music — the festival of Purim (14 Adar or Adar Bet). 

Celebrating sacred grains

On the Passover Seder, we eat special crackers, matzah, to honor the coming wheat harvest and read the story of the Jewish exodus from Egypt in the Haggadah booklet. Photo: Inna Reznik

One month later, hard work begins again. It’s time for the grain harvest and another festival, Pesach, which begins on the 15th of Nisan (late March or early April).

Pesach opens with the Seder night, probably the most festive meal in the entire Jewish year. All gather around for a long evening of reading, singing, storytelling, praying, eating, and wine-guzzling. Everyone is there — even crazy cousin George.

On this evening and throughout the next seven days, Jews eat unleavened bread called matzah. Eating this staple food in a ritualized setting reinforces the importance of the imminent wheat harvest. 

In biblical times, however, the first grain to ripen in the Land of Israel was barley, a hardier crop that matured earlier than wheat. On the second day of Pesach, an offering of newly harvested barley was brought to the Temple in Jerusalem, marking the official start of the harvest season. From that point on, farmers counted their grain bales, and Jews today symbolically count the bales during the seven-week period known as Sefirat HaOmer.

Throughout Israel, this daily count is still announced on television and radio broadcasts.

The Omer period spans the end of spring and the beginning of summer, when the fields in Israel dry out completely. Farmers collect all the dry weeds around the fields and burn them in controlled fires, and Jews commemorate this agricultural turning point by lighting bonfires on the 33rd day of the Omer, called Lag BaOmer. 

Goats and grapes 

Sefirat HaOmer concludes in early summer, when lambs and kids stop nursing and start eating grass. But the mother sheep and goats are still full of milk, so it’s time to make cheese. Jews celebrate this period with the holiday of Shavuot (“weeks” in Hebrew), when we decorate our homes and synagogues with flowers and branches and eat delectable cheesecakes.

The next harvest arrives in midsummer, when grapes are ready to be picked. Harvesting begins before sunrise, while the grapes are still covered in dew. Farmers send their sons and daughters into the vineyards dressed in white garments. If one farmer sees his family's white garments brushing up against those of another family, it’s a cause for celebration — a match has likely been made. This tradition is remembered in Tu B’Av, the Jewish holiday associated with love and matchmaking.

The dry season

The end of Av and the final month of the Jewish year, Elul, make up Israel’s driest season — a long, rainless stretch when farmers can do little more than wait. 

In modern Jewish communities, this period is marked not by flashy holidays but by Selichot — pre-dawn penitential prayers that reflect the same posture of humility and anticipation felt in the fields.

Elul, then, becomes a month of pause and preparation: The land is dry, the skies clear, and people prepare themselves — spiritually and practically — for the renewal that the coming rains will, b’ezrat HaShem (with God’s help), bring.

FAQ

What year is it in the Jewish calendar?

It's year 5786 in the Jewish calendar (or the "Hebrew calendar"), counted from the creation of Adam.

Jewish years are traditionally written using Hebrew letters, each of which has a numerical value. Thus, 5786 is written as תשפ"ו — which can either be pronounced as a letter-by-letter initialism (Tav-Shin-Pei-Vav) or an acronym (tashpav).

The Jewish year is used on official Israeli documents, in correspondence between traditional Jewish communities in the Diaspora, and on Jewish gravestones worldwide.

Does Israel use the Jewish calendar?

Israel uses both the Jewish and Gregorian calendars.

All Israeli state holidays, including secular holidays, are observed on their Jewish dates. For instance, Independence Day (Yom Ha’atzmaut) is observed on the 5th of the month of Iyar (beginning of May).

But both Jewish and Gregorian dates are used on government documents, and most Israelis use the Gregorian calendar to organize our day-to-day lives.

Do Jews really believe the world is only 6,000 years old?

Sort of.

Jews use the year 5786 to mark the passage of time since the creation of Adam, not necessarily since the creation of the universe itself. The 6,000-or-so years of history roughly correspond to the invention of writing and the beginning of modern civilization.

The Torah states that Adam was created on the sixth day of creation. But what about the preceding five and a half days? How long did they really last?

Rabbi Moses ben Nachman Girondi (nicknamed “Ramban”) — a 13th-century philosopher and physician — wrote that the first days of creation can’t be measured as 24-hour periods in the modern sense, since there was no sun to mark days and nights. Building on ideas like these, Jewish scholars have found room within tradition to reconcile the biblical creation story with modern cosmology, speculating that the early “days” of creation may have lasted for billions of our years. 

Contemporary science estimates the age of the universe at about 13.8 billion years — a figure compatible with a nuanced reading of Genesis.

Why do Jewish holidays change dates?

Jewish holidays technically don’t change dates. They always fall on the same dates within the Jewish calendar.

That said, they can appear to shift a bit from year to year if you’re accustomed to the more widely used Gregorian calendar. Because the Jewish calendar balances lunar months with the solar year, however, Jewish holidays always fall within the same general season — no matter which calendar you’re using.

How many Jewish holidays are there?

Jews have 13 significant religious holidays: Rosh HaShanah, Yom Kippur, Sukkot, Simchat Torah, Hanukkah, Tu B’shvat, Purim, Pesach’s first night (Seder), Pesach’s last night, Lag BaOmer, Shavuot, Tisha B’Av, and Tu B’Av.

Israel also has three significant state holidays: Yom HaShoah (Holocaust Remembrance Day), Yom HaZikaron (Memorial Day), and Yom HaAtzmaut (Independence Day).

Why do Jews have so many holidays?

Jews have many holidays because Judaism is one of the oldest continuously existing organized religions in the world.

The older a religion becomes, the more significant events it goes through, which manifest themselves as holidays.

How does Shabbat work in places without a normal sunset?

Shabbat is always observed for about 25 hours, whether you’re marveling at the midnight sun in Murmansk or praying through the polar night in Antarctica. But timing for candlelighting and fulfilling other Shabbat-related mitzvot in extreme latitudes varies depending on which Jewish authority you consult.

A rabbi may instruct you to follow the timing used in the nearest Jewish community of significance. For example, researchers at the South Pole may observe according to the timing in Melbourne.

Alternatively, you may be advised to observe Shabbat according to your last point of departure that had normal sunsets. That logic applied to Israeli astronaut Ilan Ramon for the two celestial Shabbatot he observed in outer space, where the sun rose and set every 90 minutes. Ramon started and ended Shabbat based on its observance in Cape Canaveral, Florida, where the Space Shuttle Columbia launched.

When humankind settles the moon, Jewish citizens of Lunarland living near the equator will experience roughly 350-hour stretches of sunlight followed by equal stretches of night. They may observe Shabbat based on the custom of their ancestors’ earthly communities or the location from which their starship launched.

*Fun Facts and Footnotes

One of my professors at Tel Aviv University, the renowned Israeli historian Michael Harsgor, studied for his doctorate at the Sorbonne University in Paris. During one of his final exams, he was the last student scheduled to appear before the panel that day. The examiners were tired, so they told him, “We’ll ask you one question. If you answer correctly, you’ll pass the course. If not, we’ll flunk you. Are you game?”

He was.

They asked, “What happened in the Western world on October 10, 1582? Who was born? Who died? What wars were fought? What communities were struck with plague?”

He answered, “Nothing happened,” and graduated summa cum laude. How? 

He knew there was no such day in the calendar.

When Pope Gregory’s committee rolled out the Gregorian calendar, they decreed that the day after October 4th would jump to October 15th that year, thereby erasing the extra two weeks that had accumulated with the Julian calendar over time.

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About the Author

Karl Walter is a licensed Israeli tour guide with over 30 years of experience leading thousands of travelers across the country he calls home.

A trained botanist, polyglot, and cave crawler, he combines deep knowledge of Israel’s history, culture, and landscapes to craft highly personalized, unforgettable journeys.

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Me crawling out of a cave in Beit Guvrin. All photos are my own, unless otherwise noted.