How often does Hanukkah start at Christmas?

For the first time since 2005, the first night of Hanukkah will fall on the same day as Christmas.

The two winter holidays meet an average of five times a century, according to Rabbi Joseph Potasnik, Executive Vice President of the New York Board of Rabbis.

Since 1900, the first night of Hanukkah has fallen on December 25 five times: 1910, 1921, 1959, 2005, and now 2024. The first night of Hanukkah, which begins on the 25th day of the Jewish month of Kislev, changes years to year. because the Jewish calendar relies on a lunar calendar, based on how long it takes the moon to go around the sun. The lunar calendar is about 354 days long, as opposed to the 365-day solar calendar, which is the time it takes for the Earth to revolve around the sun.

The shorter lunar calendar means that from one year to the next, Hanukkah, which lasts eight nights, will start 11 days earlier. Hanukkah can begin as early as Thanksgiving, but New York Rabbi President Elie Weinstock notes that the Festival of Lights always takes place in the winter because Jewish tradition requires holidays to occur in specific seasons.

To account for that, the Jewish calendar has leap years, which add an additional 13th month. “The way this works is that the sun on the moon is in the exact same position every 19 years,” Weinstock says. “In the 19-year cycle there are seven leap years.”

While Hanukkah and Christmas are celebrated by different religions, the two share similar messages around the need for more goodness and peace around the world. “It is a mitzvah to bring light into the world. If you look at Christmas, it’s about bringing light and love,” says Potasnik. “We both believe we have a special obligation to enlighten this world with love and kindness.”