Editor’s note, December 25, 8 am ET: This story is being republished for the holiday season. It was originally published in 2020.

It might seem unbelievable given that the “Christmas creep” now begins before Halloween, but the true Christmas season actually starts on Christmas Day itself. That’s right: December 25 marks the official start of the 12 days of Christmas, the Christian tradition that shares its name with a relentlessly stick-in-your-head Christmas carol.

Here are a few things you may not know about the song and the season.

What are the 12 days of Christmas?

The 12 days of Christmas is the period in Christian theology that marks the span between the birth of Christ and the coming of the Magi, the three wise men. It begins on December 25 (Christmas) and runs through January 6 (the Epiphany, sometimes also called Three Kings’ Day). The four weeks preceding Christmas are collectively known as Advent, which begins four Sundays before Christmas and ends on December 24.

Some families choose to mark the 12-day period by observing the feast days of various saints (including St. Stephen on December 26) and planning daily Christmas-related activities, but for many, things go back to business as usual after December 25.

“The 12 Days of Christmas” is also a Christmas carol in which the singer brags about all the cool gifts they received from their “true love” during the 12 days of Christmas. Each verse builds on the previous one, serving as a really effective way to annoy family members on road trips.

The lyrics to “The 12 Days of Christmas” have changed over the years

The version most people are familiar with today begins with this verse:

On the first day of Christmas,

my true love gave to me

a partridge in a pear tree.

The song then adds a gift for each day, building on the verse before it, until you’re reciting all 12 gifts together:

Day 2: two turtle doves

Day 3: three French hens

Day 4: four calling birds

Day 5: five gold rings

Day 6: six geese a-laying

Day 7: seven swans a-swimming

Day 8: eight maids a-milking

Day 9: nine ladies dancing

Day 10: 10 lords a-leaping

Day 11: 11 pipers piping

Day 12: 12 drummers drumming

The history of the carol is somewhat murky. The earliest known version first........

© Vox