As fans of Fox’s seminal teen drama "The O.C." know, December brings not only Christmas and Hanukkah but also Chrismukkah, the mostly fake holiday that becomes a bit more real this year as the two observances overlap once again. Hanukkah begins this year on Dec. 24, aka Christmas Eve, and stretches to New Year’s Day.
The last time the Jewish holiday crossed over with Christmas was 2011. That year, Dec. 25 fell roughly in the middle of the Festival of Lights, as it will again in 2019. Even more rare are the years when Hanukkah starts precisely on Christmas Day, as they did in 2005 and 1959 before that.
So why all the moving around? Rabbi Benjamin Blech, a Talmud professor at New York City’s Yeshiva University, recalled an old routine about Jewish holidays.
“They always come late or they come early. They never come on time, just like Jewish people," he said.
In reality, Blech said, Hanukkah falls on the same date every year — just not on the calendar most are used to. Jewish holidays are based on the Hebrew Calendar, which is lunar, he said, as opposed to secular Gregorian calendar used by much of the world, which is solar.
“In the Bible, God tells the Jewish people to look at the moon and count the days from there,” Blech said. “The moon goes through its phases. It’s obvious. It can be seen and record time.”
The trouble, he explained, is that a lunar year lasts about 354 days, far shorter than the 365 and a quarter days that make up the secular solar year. Muslims, who set their holidays on their own lunar Islamic calendar, ignore the difference. That’s why the holy month of Ramadan moves about the Gregorian calendar, creeping back about 10 days each year.
The Hebrew calendar makes up for the difference, however, by adding a leap month during seven of every 19 years, Blech said. That’s because the Bible dictates that another Jewish holiday, Passover, must fall in the spring.
“The minute you’ve got a leap month, you are now a little bit ahead of normal,” Blech said.
And so Hanukkah keeps moving, on most calendars at least. It bumped back to November in 2013, resulting in Thanksgivukkah.
As to the special significance of Christmas and Hanukkah coinciding— for non-O.C. fans, that is — the rabbi sees a message of commonality.
“It’s a way of saying that, deep down, we share a lot of stuff, if you want to go that way,” Blech said.