(RNN) - This year marks a rare holiday that won't happen again for more than 76,000 years - Thanksgivukkah.
Thanksgivukkah is a mashup of Thanksgiving and the Jewish holiday Hanukkah - and this year is only the second time it's happened since the creation of Thanksgiving in 1863.
The holidays rarely match up because Thanksgiving is based on the Gregorian calendar, which is followed by most of the world, and Hanukkah is based on the Hebrew calendar.
Traditionally Thanksgiving falls on the fourth Thursday in November, and Hanukkah falls between the 25th day of the month Kislev and the second or third day of the next month, Tevet. The Hebrew calendar shifts one day from the Gregorian calendar about every 231 years.
The last time the two holidays aligned was in 1888. Lincoln established Thanksgiving as a national annual tradition in 1863 during the height of the Civil War.
But as the holiday draws closer, it had us thinking - what will the next Thanksgivukkah be like about 760 centuries from now?
The biggest question is whether humans will still be here to celebrate. Thanksgivukkah may be a twice in a species event, not just once in a lifetime.
To give you some perspective on just how massive an that time frame is, humans discovered writing just more than 5,000 years ago.
For even more perspective, construction on the Great Pyramid of Giza began about 4,597 years ago.
But, if we go out on a limb and say people still exist - or have been replaced by alien life forms to celebrate in our stead - we can say turkey or chicken might still be on the dinner table.
While they have obvious physical differences, turkey and chicken are both part of the same biological family, which first appeared 30 million years ago, according to the Natural History Museum of Los Angeles County.
But the "I survived Thanksgivukkah" T-shirt you get won't survive the wait - cotton deteriorates pretty fast if left out in the open. According to the National Park Service, cotton decomposes in one to five months, and we don't think your closet will survive 76,000 years. The oldest building in the world is located in France, and it's a grave.
In fact if we all died on Thanksgivukkah - maybe of too much food - some of the only man-made objects left for the next one might be made of glass. According to the EPA, plastic bottles take about 450 years to decompose, while glass bottles take a whopping 1 million.
And who knows about the weather? We're still in the middle of an ice age, according to scientists, but it varies in intensity. According to professor Kirk A. Maasch with the University of Maine, our last cooling period was at its height 20,000 years ago. The planet's been warming up since then, but there's no telling when it will go back into the deep freeze.
One thing that won't change is Polaris, the North Star - or, rather it will have swung back around for the third time to be the star directly over the North Pole. The earth goes through a complete cycle of North Stars roughly every 25,800 years, according to a University of Michigan press release.
Long story short, don't expect to catch the next Thanksgivukkah. According to Ancestry.com, the average human generation is 25 years. That's at least 3,040 offspring, in order, before the next Thanksgivukkah. If you bury your time capsule now, maybe you'll win the impossibility lottery and someone will open it just in time for the third Thanksgivukkah.
Meanwhile, our best advice is to enjoy the camaraderie of family and friends, eat some turkey and matzo and ignore your next Thanksgivukkah planning in favor of Christmukkah on Dec. 25, 2016.
Copyright 2013 Raycom News Network. All rights reserved.
IF YOU HAVE A STORY IDEA CONTACT WLBT/WDBD AT (601) 960-4426 OR EMAIL US AT News@WLBT.COM.
715 South Jefferson Street
Jackson, MS 39201