Ari Eloum, owner of the Kosher Pastry Oven in Silver Spring, sells Hannukah donuts with a pumpkin filling on Monday. (Evelyn Hockstein /For The Washington Post)

For most American Jews, the Hanukkah script has been pretty clear for decades: Light candles in menorahs, make potato pancakes (called latkes), play a game with a spinning top (called a dreidel), sing songs, give presents and call it a night (or eight, in this case).

Then came the menurkey of 2013. And greetings cards of pilgrims wearing the long, curly sideburns of the Orthodox. And debates about whether cranberry sauce goes with latkes.

Witness the messy process of holiday-creating, and on a lightning-fast scale. That’s because of the extremely rare overlap Thursday of Thanksgiving and the first full day of Hanukkah, which usually falls well into December. Some calendric experts say the event many are calling Thanksgivukkah happens once a century; others say it won’t happen for thousands more years.

The merger of two largely happy, fun holidays has triggered a rush of kitschy marketing, including the sale of thousands of ceramic, turkey-shaped menorahs called menurkeys. It has also prompted a flood of new recipes and debate on food blogs about how to appropriately mess with two holiday menus that for many are cherished just as they are, thank you.

But it has also triggered a more deliberate look for many American Jews at a holiday that’s not been considered particularly important.

“I’m agonizing over whether to get a serious or silly Hanukkah card — and I never even buy Hanukkah cards!” said Sara Finer, 32, a lawyer from Rockville who on Monday was in a CVS card aisle in downtown Washington.

Finer was buying a card to go with a gift for an in-law’s cousin whom she normally wouldn’t see on Hanukkah, but for the fact that it’s falling when the family gathers for Thanksgiving. Because some people coming to dinner won’t be Jewish, Finer said she’s paying more attention to how she will explain Hanukkah. “I was literally Googling it at work.”

The merger is prompting some Jews to give fewer or no Hanukkah gifts this year. Many others are doing the opposite, noting — like Finer — that because of Thanksgiving and the accompanying school vacation, they will be around many more relatives than usual on Hanukkah and want to include people who usually aren’t on the gift list. Some are writing short narratives about the history of American Jews to be read at the Thanksgiving table as a complement to the secular holiday’s place in U.S. history.

“This is happening once in a lifetime — the idea of Thanksgiving and being thankful for this country and what it’s allowed American Jews to become. My grandparents came from the shtetl,” a small, poor European village, said Larry Bram, an Easter Seals executive who lives in Silver Spring. He has stocked up on Thanksgivukkah T-shirts, turkey hats with payos (the long curls) attached, a pumpkin version of the traditional Hanukkah doughnuts and a piñata for the children that looks like a bumblebee wearing a yarmulke. “This is a fun time, and we hope to be goofy and thankful simultaneously.”

The holiday convergence has created a unique opportunity for marketers, who are labeling their gear “For final sale.” Among the best-selling items has been the $50 menurkey, which was created by a fourth-grader in New York who got it going on Kickstarter.

Kristen Kreider, director of retail operations at the National Museum of American Jewish History in Philadelphia, said she had to hire extra staff to deal with the hundreds of boxes of menurkeys going out each day. Another popular item, she said, is a greeting card in which a turkey and an ancient Jewish warrior square off. The front says: “What did the turkey say to the Maccabee?” And inside: “You think you’ve got problems?”

When Hanukkah falls earlier in the calendar, apart from the traditional Christmas season, Kreider said, “it’s usually the kiss of death from a retailer’s perspective. But with Thanksgivukkah, you’re going to be with relatives, what are you supposed to do? You’re with 10 nieces and nephews. You’re not going to give them a little something? This has brought Hanukkah to the forefront.”

How rare Thanksgivukkah is remains a topic of debate, because it’s a question of analyzing and predicting the part-lunar, part-solar Jewish calendar and the Western calendar, which is lunar. Some experts say the convergence hasn’t happened since 1888 and won’t again for more than 70,000 years. Others say it happened in 1918 and will again in 2070.

The bigger debates are about food — and what constitutes something really “Jewish” and something really “American.” For example, because the original story of Hanukkah involves a small amount of lamp oil miraculously lasting eight nights, oil is the key to the holiday — thus the classic deep-fried potato latkes and doughnuts. But what about a deep-fried turkey? Is that legit?

Tina Wasserman, author of several popular cookbooks on Jewish food, said people worry too much about messing with food traditions.

“Our food tells stories. The question is, did the story come first and create the food, or does the food come first and create the story?” she said. She is advising the torrent of people with Thanksgivukkah questions on food blogs and her Facebook page that if they’re uncomfortable merging a recipe, just include two classics — like mashed potatoes and latkes.

“This is the one holiday when you can put another carb on the table and no one will complain,” she said.

In some places, the merger wasn’t positive. Jewish customers online reported seeing fewer Hanukkah items in grocery stores because shelves were being taken up with Thanksgiving items. The Kosher Pastry Oven in Silver Spring, which usually makes a killing on their pecan and pumpkin pies on Thanksgiving and then a few weeks later on their doughnuts, said business suffered a little as customers had to choose.

Sarah Meytin, 37, always puts thought into Hanukkah, hosting a party for family, giving gifts and thinking carefully about how to communicate to her children, ages 5 and 7, about the history of the holiday, which commemorates a historic Jewish victory over oppression.

But this year, she did more. Considering the merger with Thanksgiving, the preschool director made her own menurkey by hand and raised money with her children to feed a family in need over the holiday.

Some people she knows are marking the holidays separately so they don’t lose the uniqueness of either, said Meytin, who lives in Silver Spring. “But I felt, how can we have this holiday about giving thanks and it happens to fall on Hanukkah — this unique occurrence in our lifetimes — and not honor that in a unique way?”