Jewish Holiday Calendar: Understanding the Hebrew Calendar Cycle

A Calendar Between Sun and Moon

The Hebrew calendar is one of the oldest continuously used calendrical systems in the world. Unlike the purely solar Gregorian calendar or the purely lunar Islamic calendar, the Hebrew calendar is lunisolar: months follow the moon, but leap months are periodically added to keep the calendar aligned with the solar seasons. This ensures that Passover always falls in spring and Sukkot always in autumn, even as the specific Gregorian dates shift.

How the Hebrew Calendar Works

The Hebrew year has twelve months in a common year and thirteen in a leap year. Months are 29 or 30 days long, based on the lunar cycle. A 19-year Metonic cycle adds seven leap months at prescribed intervals (years 3, 6, 8, 11, 14, 17, and 19 of the cycle), keeping the calendar within bounds.

The Gregorian Drift

Because of the leap month system, Jewish holidays move within a range of about five to six weeks on the Gregorian calendar. Rosh Hashanah can fall anywhere from early September to early October. Passover ranges from late March to late April. This moderate variability makes planning possible but requires checking specific dates each year.

The High Holy Days: September-October

Rosh Hashanah: 1-2 Tishrei

The Jewish New Year begins a ten-day period of self-examination and repentance. It falls in September or early October. Synagogues hold special services with the sounding of the shofar. Families gather for festive meals with symbolic foods. In Israel, it is a two-day public holiday when most businesses close.

Yom Kippur: 10 Tishrei

The Day of Atonement is the holiest day in the Jewish calendar. A 25-hour fast from sunset to sunset is observed by the majority of Jews worldwide, including many who are otherwise secular. In Israel, the entire country comes to a standstill: no public transportation, no broadcasts, and streets empty of cars. Even in the diaspora, synagogues see their highest attendance of the year.

Sukkot: 15-21 Tishrei

The Festival of Booths follows five days after Yom Kippur. Families build temporary structures called sukkot, eat meals inside them, and wave the lulav and etrog. The seven-day festival is followed by Shemini Atzeret and Simchat Torah, extending the holiday period. In Israel, the first day is a public holiday. In the diaspora, the first two days and the last two days are full observances.

Hanukkah: 25 Kislev (November-December)

Hanukkah's eight nights fall in November or December, as discussed in the December calendar. While not a major religious holiday in terms of observance requirements, it has become culturally prominent, especially in the United States, where its proximity to Christmas amplifies its visibility.

Passover: 15 Nisan (March-April)

Passover commemorates the Exodus from Egypt and is one of the most widely observed Jewish holidays. The Seder meal on the first night (first two nights in the diaspora) follows a specific order of rituals, readings, and symbolic foods. Matzah replaces bread for the eight-day festival, and many families thoroughly clean their homes to remove all chametz (leavened products).

Business Impact

During Passover week, Israeli businesses operate on a holiday schedule. In the United States, kosher food industries shift production significantly. Restaurants and catering services offering Passover menus see strong demand. Schools with significant Jewish enrollment may schedule spring breaks to overlap with Passover.

Shavuot: 6 Sivan (May-June)

Shavuot, falling seven weeks after Passover, celebrates the giving of the Torah at Mount Sinai. Traditions include all-night Torah study sessions, dairy meals, and the reading of the Book of Ruth. It is a public holiday in Israel and observed with special services in the diaspora.

Planning With the Hebrew Calendar

For reliable scheduling, use a Hebrew calendar converter at the start of each Gregorian year to map all major holidays. Pay special attention to the September-October High Holy Day period, which can span three to four weeks of interrupted scheduling. In industries with significant Jewish participation, particularly finance, media, and law in major metropolitan areas, these dates materially affect operations.