The major Jewish religious holidays were set forth in the Torah. To these were added holidays that celebrate or commemorate specific events that occurred in Jewish history. Jewish holidays and commemorations are observed according to the Hebrew modified lunar calendar, and therefore the date according to the Gregorian calendar changes each year.

Because of the uncertainty of determining dates in ancient times, it became a custom to add an extra day to many of the holidays celebrated in the Diaspora. Therefore, the Israeli holiday calendar is slightly different from that observed abroad by Orthodox and Conservative Jews. Reform Jews do not celebrate the second day of certain holidays such as Shavuot. The Jewish day ends and begins and ends at sundown, and therefore holiday observances always begin in the evening. Some commemoration days are moved to a different day if they fall on a Shabbat (Saturday).

Three holidays were singled out in the Torah as “regalim” – holidays that required a pilgrimage to Jerusalem by the entire people of Israel. These are Sukkot (tabernacles) Pessah (Passover) and Shavuot.

Rosh Hashanah
Rosh Hashanah is the Jewish new year. It is celebrated in the fall. At Rosh Hashanah a Shofar (Ram’s horn) is blown to signal the arrival of the new year. It takes place on the first day of Tishrei, usually in September. It is followed by 10 days during which, according to tradition, judgment is passed on each person, the judgment being sealed on Yom Kippur.

Yom Kippur – the fast day of atonement, on the tenth of Tishrei, on which Jews ask God for forgiveness for their sins. In addition to the fast, Yom Kippur is marked by having five sets of prayers.

Sukkot (“tabernacles”) begins on the fifteenth day of Tishrei. Sukkot lasts seven or eight days and commemorates the temporary houses in which Jews dwelt on their departure from Egypt, as well as marking the shacks built in the fields to bring in the autumn harvest. During Sukkot, Jews spend their days in outdoor structures that must have roofs that are slightly open to the stars.

Simhat Torah – marks the conclusion of the yearly cycle of Torah readings. In Israel, it coincides with Shmini Atzeret, the eighth and concluding day of Sukkot. Orthodox Jews mark Simchat Torah by dancing in the streets and Torah processions.

Hanukkah – The holiday of Hanukkah commemorates the victory of the Maccabees over the Seleucid Greeks and the liberation of Jerusalem in the second century BC. It takes place on the 25th day of Kislev according to the Hebrew calendar, usually in December. Hanukkah. According to rabbinical tradition, a miracle occurred during Hanukkah, allowing the lamps of the newly liberated temple to be lit for eight days using consecrated oil that should only have sufficed for a single day.

Purim – The holiday of Purim, on the 14th day of the month of Adar, marks the rescue of the Jews of ancient Persia by the Jewish queen Esther and her uncle Mordecai from a genocidal plot of the evil minister Haman. It is celebrated by a masquerade carnival.

Passover – Passover, celebrated beginning on the 14th day of the month of Nissan, usually in April, commemorates the liberation of the Israelis from bondage in Egypt. It is celebrated by a ritual feast (Seder) and lasts 7 days. During this time Jews must eat Matzot, unleavened bread, and refrain from eating bread or leavened baked foods of any kind, in commemoration of the unleavened bread that the Israelites ate on leaving Egypt.

Yom Hashoah Ve Hagevurah – Holocaust Memorial Day – Israel marks the memory of Holocaust victims on the 27th day of Nissan, which falls in late April or early May. The date was chosen to commemorate the Warsaw Ghetto revolt.

Israeli Memorial day – Israel’s memorial day for fallen soldiers and terror victims is marked on the fourth day of Iyar, one day before the celebration of Independence Day.

Israel Independence day – Israel Independence day is celebrated on the fifth day of Iyar. It marks the termination of the British mandate for Palestine and the renewal of Jewish sovereignty in Israel after 2,000 years of exile, on May 15, 1948 according to the Gregorian calendar.

Shavuot – Shavuot is celebrated on the 50th day (seven weeks) after Passover. It is both a harvest holiday and a holiday that commemorates the giving of the Torah to the Jewish people at Mount Sinai. Shavuot usually falls in late May or early June.

Tish’a Be’av – The 9th day of the month of Av, which usually falls in August, is a day of fast and mourning for the destruction of both the first and second temples, both of which took place on the same day of the year according to tradition.