Why Does Hanukkah Change Dates Every Year?

Hint: It has to do with very specific calendars

Hanukkah is an eight-day Jewish holiday that’s observed in late fall or early winter. Hanukkah, with its own set of traditions, celebrates the victory of a band of Jewish warriors over their oppressors. It also commemorates the miracle God performed when a vial of oil—needed to rededicate the Holy Temple in Jerusalem—lasted for eight nights instead of one. There’s plenty of rich history behind Hanukkah, but there’s one common question you may have about the holiday: When does Hanukkah start, exactly?

It’s a valid question, given the fact that Hanukkah’s dates change each year. Here’s why people wish loved ones a happy Hanukkah on a different day every year, how long the Festival of Lights lasts and when Hanukkah will happen this year. Before the festivities begin, don’t forget to read up on what the Hanukkah colors are and if Chrismukkah is a real holiday.

Why does Hanukkah change dates every year?

Most American and Christian holidays are celebrated according to a 365-day Gregorian (or solar) calendar. The observance of Jewish holidays, however, follows a lunisolar calendar—one that keeps track of the earth’s orbit around the sun to determine a year’s length but also factors in the phases of the moon to determine the beginning and end of each new month.

The dates on these two calendars don’t neatly match up, so Hanukkah appears to change dates every year. On the Hebrew calendar, though, it always begins on the 25th of Kislev, the same as the date of the very first Hanukkah celebration.

What are the differences between a lunar and solar calendar?

A lunar month is shorter than a solar one, at 29.5 days, so 12 lunar months only add up to about 354 days. “The rabbis who ultimately set the calendar knew if [they used] a truly lunar calendar, the holidays would march backward by eleven days every year. If you have a holiday that celebrates the harvest in October, you can’t have it coming in June,” says Rabbi Norman Patz, rabbi emeritus of Temple Sholom of West Essex, in Cedar Grove, New Jersey, and visiting rabbi of Temple Beth Shalom in San Juan, Puerto Rico. “It had to be reconciled with the solar calendar,” which is how we ended up with a lunisolar one.

In addition, rather than adding a leap day every four years like the Gregorian calendar, the Jewish or Hebrew calendar adds an entire leap month to seven out of every 19 years, using a complicated formula. Because of this, a year in the Hebrew calendar can range from 353 to 385 days.

How long is Hanukkah?

Like all Jewish holidays, Hanukkah starts in the evening. It is observed for eight consecutive nights, as we recall the miracle that occurred when the oil in the Temple lasted for eight days instead of one. In fact, the eight menorah candles represent the eight nights the oil lasted. Though the dates of the holiday may change on the solar calendar, the length of the holiday never does.

When does Hanukkah start?

In 2022, Hanukkah begins on the evening of Dec. 18, with the last night falling on Dec. 26.

Because of the varying lengths of the lunisolar calendar, Hanukkah sometimes falls around the American holiday of Thanksgiving. In 2013, Hanukkah and Thanksgiving coincided, creating a freaky once-in-a-lifetime double holiday, “Thanksgivukkah,” for American Jews. Hanukkah can begin as early as Nov. 28 and as late as Dec. 27, depending on the year.

Usually, though, Hanukkah starts sometime in December. Because of this fact, and the modern tradition of giving gifts at Hanukkah, many people have come to believe that Hanukkah is a sort of “Jewish Christmas,” but nothing could be further from the truth. Hanukkah actually began nearly 600 years before the first Christmas celebration. Hanukkah and Christmas have overlapped over the years, though. In 2005, Hanukkah began on Dec. 25—and that will happen again come 2024.

Why does Hanukkah always start in the evening?

In the story of creation as told in the book of Genesis, the description of each day concludes with the phrase, “And there was evening and there was morning,” leading rabbis to determine that a day begins with evening. Therefore, holidays, like all other days in the Hebrew calendar, commence in the evening.

Laurie Budgar
Laurie Budgar is an award-winning journalist specializing in lifestyle, health, travel and business, and contributes regularly to RD.com as well as other national magazines and websites. Her superpower is making complex information not just easy to understand, but lively and engaging as well. Budgar is also a certified speech-language pathologist (MS, CCC/SLP) who spent over a decade helping people with brain trauma, stroke, MS, Alzheimer's and other neurological conditions regain language, speech, swallowing and cognitive skills.