How Does the Jewish Calendar Work? A Bible Study

Quick answer: The Jewish calendar follows both the moon and the sun. Each month begins with the new moon (Rosh Chodesh) and lasts 29 or 30 days, and seven times in 19 years an extra month is added so Pesach stays in the spring (Deuteronomy 16:1). Days begin at sunset (Genesis 1:5). The feasts God commanded are listed in Leviticus 23, and later holidays like Purim and Chanukah remember how God saved His people.

What is the Jewish calendar?

The Jewish calendar, or Hebrew calendar, is the calendar the Torah uses. It sets the dates of Shabbat, the new moons and every holiday. It is also how a bar or bat mitzvah date is set: by the Hebrew date of the birthday.

Who is this study for?

This study is for young people getting ready for bar or bat mitzvah, for parents, and for anyone who wants to know why Jewish holidays “move” on the regular calendar. They don’t really move. They are keeping time by a different clock.

The study has six parts. Each part ends with a quick quiz and questions you can think about on your own or talk over with your family. For this year’s dates, see our holiday calendar.

What is Rosh Chodesh?

Quick answer: Rosh Chodesh, “head of the month,” is the day of the new moon. The Torah gave it special offerings, and today we mark it with added prayers, Hallel and a Torah reading.

Rosh Chodesh means “head of the month.” It is the day of the new moon, and it is a small holiday.

In the Torah. Parashat Pinchas lists special offerings for it: “And in the beginnings of your months ye shall offer a burnt offering unto Hashem” (Numbers 28:11–15). The priests also blew trumpets “in the beginnings of your months” (Numbers 10:10). In King Shaul’s house, the new moon was a family feast (1 Samuel 20:5, 18).

Watching the sky. In ancient times, the new month began when two witnesses saw the first thin sliver of the new moon and told the Sanhedrin, the high court in Jerusalem. The court declared the new month, and messengers and fire signals on the hilltops spread the news (Mishnah Rosh Hashanah 2:2–7).

A calendar for the exile. As the Jewish people were scattered, it became hard to send messengers. Around the year 359, the sage Hillel II published the rules for calculating the calendar, so Jews everywhere could keep the same holidays on the same days. We still use his calendar today.

How we mark Rosh Chodesh today.

• On the Shabbat before, the new month is announced in synagogue with a special prayer.
• On Rosh Chodesh we add Ya’aleh v’Yavo to our prayers and to the blessing after meals, say part of Hallel (Psalms 113–118), and read Numbers 28:1–15 from the Torah.
• When a month has 30 days, Rosh Chodesh lasts two days.
• Rosh Chodesh is a special day for women. A tradition says the women of Israel would not give their gold for the golden calf, so they were given the new moon as their holiday (Pirkei de-Rabbi Eliezer 45).

A picture of renewal. The moon gets smaller and disappears, then comes back. The sages saw it as a picture of Israel, which seems to fade but always shines again.

What are the feasts of Hashem?

Quick answer: Leviticus 23 lists them: Shabbat, Pesach and Unleavened Bread, the Omer, Shavuot, Yom Teruah, Yom Kippur, Sukkot and Shemini Atzeret. God calls them “My feasts.”

Parashat Emor gives the full list of the holidays in Leviticus 23. It begins, “These are the feasts of Hashem… even these are My feasts” (Leviticus 23:2). They are not just Jewish holidays; God calls them His own appointments.

Three pilgrim feasts. Pesach, Shavuot and Sukkot were the times every Jewish man went up to Jerusalem (Deuteronomy 16:16). Each one remembers something God did and celebrates a harvest.

Holy convocations. The Torah calls these days mikra’ei kodesh, “holy gatherings” (Leviticus 23:2). On most of them, work is stopped as on Shabbat, except that cooking for the holiday is allowed.

Two in spring, the rest in fall. The spring feasts tell the story of leaving Egypt and receiving the Torah. The fall feasts are about repentance, atonement, and joy in God’s presence. Parashat Pinchas (Numbers 28–29) gives the offerings for each one.

What do the feasts teach us about Mashiach?

Quick answer: Yeshua kept the feasts. He died at Pesach and rose at the Omer, the Ruach came at Shavuot, and the fall feasts point to his return. Shaul still said, “Let us keep the feast.”

Yeshua lived by the Jewish calendar. “His parents went to Jerusalem every year at the feast of the passover” (Luke 2:41). He went up for Sukkot and, on its last great day, called out, “If any man thirst, let him come unto me, and drink” (John 7:2, 37). He was in the Temple at Chanukah (John 10:22). His last meal with his disciples was at Pesach.

The feasts point to Mashiach. The Brit Hadashah (New Testament) connects the spring feasts to Yeshua’s first coming:

The fall feasts look ahead. Many Messianic teachers see the fall feasts as pictures of Mashiach’s return: the great shofar (Isaiah 27:13; 1 Thessalonians 4:16), Israel’s day of repentance and atonement (Zechariah 12:10), and the joy of God dwelling with His people, like Sukkot.

Notice what Shaul said. “Let us keep the feast” (1 Corinthians 5:8). Knowing what the feasts point to does not replace keeping them. It gives us one more reason to keep them with joy.

Review questions

After working through this study, you should be able to explain how the Jewish calendar works and name the feasts in order, without notes. These questions will help.

1. When does a Jewish day begin, and which verse shows it?
2. What is Rosh Chodesh, and how was it declared in ancient times?
3. Why does the Jewish calendar need leap years, and what month is added?
4. List the feasts of Leviticus 23 in order.
5. Name two feasts and explain how each one points to Yeshua.

When you learn God’s calendar, the year stops being a list of dates and becomes a story, told again every year, that leads to Mashiach.