Some of the information below will be much more than you ever wanted to know about the particular Jewish holy day, but this should help you give a well-rounded answer to your child if you are asked about a specific one. You might be wondering how the Jewish calendar works. It is not the same as the Gregorian calendar (the type you probably have on your wall or in your day planner), so even though the dates of Jewish holy days or festivals may shift on the Gregorian calendar, the dates remain fixed on the Jewish calendar. The Jewish calendar uses a somewhat complicated system made up of earth rotation, the moon's revolution around the earth, and earth's revolution around the sun. It is not a strictly lunar calendar.Rosh Hashanah“Rosh Hashanah” means “head of the year” in Hebrew, and as the name suggests, it is celebrated at the start of the Jewish calendar year, usually in late September or early October. It is a two-day festival and is 10 days before Yom Kippur, the holiest day on the Jewish calendar.Yom Kippur (also known as the Day of Atonement)There are ten days between Rosh Hashanah and Yom Kippur. This is the key day of repentance in Judaism and occurs during September or October. Observance of this holy day typically includes 25 hours of fasting and prayer.Hanukkah (also known as the Festival of Lights or the Feast of Dedication)This is the one most kids will know about because it is referenced in media frequently. “Hanukkah” comes from the Hebrew verb "חנך,” which means “to dedicate.” Hanukkah is a festival celebrated over eight days and nights in winter to commemorate a miracle in Jewish history, the Jewish revolt against Syria, and the purification of the Temple by the Maccabees. According to tradition, the Maccabean priests only had enough oil for one day, but the cleansing ceremony was supposed to last eight days. Miraculously, their oil lasted the entire eight days. Hanukkah is a kind of re-enactment of the ceremony. One branch of the chanukiah, a nine-branched menorah, is lit each night of Hanukkah until each branch is lit on the final night.In Western cultures where Christmas is celebrated, some Jewish people exchange gifts on each night of Hanukkah. Children’s games, including those using a dreidel (a spinning top), are also played. Keep in mind, though, that Hanukkah is just one of many festivals Jewish people celebrate, and it is considered “major” typically only because of its proximity to Christmas.Purim“Purim” is the Hebrew word for “lots,” and each year in late winter or early spring, Jewish people commemorate being saved from extermination. The story of Purim is chronicled in Esther, which records that a Jewish woman Esther and her adoptive father (and cousin) Mordecai saved the Jewish people from Haman, an advisor of King Ahasuerus.In celebration of Purim, the Book of Esther is read publicly in the synagogue on the evening and morning of Purim. It is also suggested that Jewish people complete acts of charity, send a gift to at least one friend, and share a festive meal with friends and family.PassoverPassover, also known as the Festival of Unleavened Bread, is usually in March or April and commemorates the events of the Israelites’ exodus from Egypt. It is a celebration of how God showed the Israelites mercy by passing over the houses of the Hebrews in Exodus 12, when all of the Egyptian first-born sons were killed as a sign of judgment. Passover lasts seven or eight days, depending on whether or not the person lives in Israel. It has two major symbols: matzo (unleavened bread also called matza or matzah) and a Seder meal (a meal that takes place on the first or second night of Passover which consists of very specific foods like bitter herbs, lamb, and wine).  Before Passover begins, all food containing leaven (yeast) is removed from the home.Pentecost (Shavuot)Also known as the Festival of Weeks, Shavuot typically falls in May or June and celebrates the harvest and giving of the Torah on Mt. Sinai. Shavuot lasts two days during which work is not allowed, and the Torah, as well as the Book of Ruth, is studied.Sabbath (Shabbat)Sabbath is a weekly day of rest and worship to commemorate the day of rest after the six days of creation, and for Jewish people, it is from Friday evening at sundown to Saturday evening.