What happens when you cross Thanksgiving with Hanukkah?

The coincidence this year of Thanksgiving and the start of Hanukkah is very unusual - it last happened in 1888. But in a way it's fitting, as American Jews have been embracing Thanksgiving for more than two centuries.

By the time the first of eight candles in Jewish menorah were lit on Wednesday evening for the start of the Jewish festival of Hanukkah, the country was largely closed down for Thursday's Thanksgiving holiday.

According to the most commonly cited calculation, not only has this not happened for 125 years, but it won't happen again for more than 70,000 years.

That is because the Jewish calendar is shifting in relation to the Gregorian calendar very, very slowly... at a rate of four days every 1,000 years.

This year's alignment has given rise to a curious new amalgam: Thanksgivukkah.

The term was coined, and trademarked, by a marketing specialist called Dana Gitell, who teamed up with an online Jewish gift shop to sell T-shirts and other memorabilia.

Among the items on sale are a "menurkey" - a menorah shaped like a turkey - designed by a nine-year-old New Yorker, whose family say they have sold thousands at $50 a piece.

There's a Facebook page with more than 13,000 "likes", a #Thanksgivukkah hashtag on Twitter, and a large number of YouTube music videos of varying quality.

Perhaps the most common online discussion topic is food, and ideas for "mash-up" recipes that combine festive delicacies from both sides - from potato latkes with cranberry applesauce to rye pumpkin pie.

All this has brought to the surface the longstanding affection for Thanksgiving among American Jews.

"American Jews love Thanksgiving and celebrate it every year with the rest of America," says Gitell.

Whereas some Jewish families might not take part in Halloween or Christmas, Gitell says she doesn't know any Jewish family that wouldn't celebrate Thanksgiving. "I think that Thanksgiving is generally considered kosher by all Jews," she says.

This is partly because Thanksgiving is generally seen as a secular, national holiday in which people honour family and community, regardless of ethnic group or religious denomination.

It is also popularly associated with pilgrims giving thanks for their new life in America, where they could practise their religion freely.

In that respect, some see similarities with the story of Hanukkah, which celebrates the miraculous lighting of the menorah in Jerusalem's Holy Temple after the victory of the Maccabees against the Syrians in the 2nd Century BC.

Though several rabbis have expressed reservations about Thanksgiving, and one even stated his opposition to eating kosher turkey, Rabbi Levi Shemtov, director of the Washington office of the ultra-Orthodox Chabad movement, says there is "nothing adverse to anything Jewish or contradictory to Judaism" in Thanksgiving.

"For that celebration to happen - as we are in our religious calendar celebrating our own religious freedom, as it was achieved in ancient times - makes it only that more emphatic," he says.

US history has also been deployed to firm up the links, right back to the use of rabbinic texts used by Puritans to thank God for their safe arrival in America.

After George Washington proclaimed the first nationwide Thanksgiving celebration in 1789, the preacher at New York's oldest congregation, Shearith Israel, gave a Thanksgiving sermon and instructed his congregation to observe the holiday.

The service was unprecedented in the history of Jewish liturgy and prayer, says Allan Nadler, a professor of Jewish studies at Drew University in Madison, New Jersey.

Greeting cards are among this year's Thanksgivukkah products

"The creation of a Hebrew religious service to commemorate a non-Jewish holiday, a holiday whose origins have nothing to do with the Jews - that's quite remarkable."

Their immediate adoption of Thanksgiving is also an example of how "Jews in general embraced everything American with real fervour", says Nadler.

"The way in which the Jews immigrated to America in the 19th Century - especially the mass wave of Russian Jews at the end of the 19th Century - the speed with they acculturated themselves and rose up economically and intellectually in universities I don't think has any parallel."

Historically, Hanukkah was a relatively minor Jewish festival, but it has gained in significance. Gifts are now often exchanged, especially in North America.

"In America it really became important because of the timing - it fitted into the 'festival season'," says Nadler. "For Jews anxious to have cultural bonds and interfaith bonds with their Christian neighbours, Hanukkah was perfect."

Currently on sabbatical in his native Canada, Nadler says he was taken aback after he arrived in the US as a graduate student and was invited by an orthodox rabbi to a Thanksgiving dinner.

He is "feeling a little forlorn" about missing the holiday this year - but he winces at the commercialisation of Hanukkah. And that goes for Thanksgivukkah, too.

Follow @BBCNewsMagazine on Twitter and on Facebook