Tonight, the Jewish holiday of Hanukkah begins on Christmas Eve. Because the Hebrew calendar is a lunar calendar, the 8 days of Hanukkah change every year. When did it last overlap with Christmas and when will it next occur?
Hanukkah has only started on Christmas proper four times in the last 100 years: 1918, 1921, 1959, and 2005. However, it has overlapped with Christmas over fifty times in the last 100 years. According to Vox, “With eight total occurrences in 117 years, Hanukkah starts on Christmas Eve or Christmas Day roughly once every 15 years.”
The next time Hanukkah and Christmas overlap will be in 2019. The next time Hanukkah begins on Christmas Day is 2024.
As stated above, the Jewish calendar is a lunar calendar. According to the United States Naval Observatory, a lunar calendar is based on lunar cycles that begin each month on the darkest day. Other calendars similar to this style are the Chinese, Hindu, and Islamic calendars. However, like the more common solar calendar, aka “Gregorian calendar,” the Hebrew calendar is made up of 7 days a week, about 4 weeks a month, and 12 months every year.
The Jewish New Year, known as Rosh Hashanah, usually occurs in late September or early October every year.
Hanukkah is 8 days long and ends on January 1, 2017 for Hanukkah 2016. To learn more about why Hanukkah is 8 days, click here.