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December Is the 12th Month of the Year

December is the first month of winter in the northern half of the world. In the southern half, it is the first month of summer.

Desembers birth flower, holly bush with red berries covered in snow.

One of December’s birth flowers is the holly.


December is the twelfth and last month in the Gregorian calendar and has 31 days. The December solstice on December 21 or 22 marks the beginning of winter in the Northern Hemisphere.

Why Is December Not the Tenth Month?

The meaning of December stems from the Latin word decem, meaning ten. The old Roman calendar started in March, making December the tenth month. When the Roman senate changed the calendar in 153 BCE, the new year started in January, and December became the twelfth month.

December Solstice

The December solstice on December 21 or 22 is also known as the winter solstice. It is the shortest day of the year in the Northern Hemisphere and marks the beginning of the (astronomical) winter season there.

In the Southern Hemisphere, it is called the summer solstice. There, it is the longest day of the year and the beginning of the (astronomical) summer season.

Christmas Eve and Christmas Day

Christmas means the Mass of Christ and is one of the central holy days for Christians. They believe Jesus Christ was born on December 25, on Christmas Day. The night before is known as Christmas Eve.

December was a month of celebration even before Christendom: In Roman times, the mid-winter festival of Saturn was celebrated – the Saturnalia. It was a time of feasting and merry-making; even slaves and their masters switched places for a while. The Saturnalia culminated with the winter solstice, which fell on December 25 in the Roman calendar.

Christmas fruit cake with decoration.

Evergreen holly leaves are symbols of new life in winter – here as decoration on a traditional fruit cake.


New Year’s Eve

As the last month of the year in the Gregorian calendar, December ends with New Year’s Eve on December 31. Many people around the world count down to the new year and celebrate with fireworks and well-wishes. Although in many other cultures, the new year begins on very different dates.

Astronomical Events in December 2024

December 13/14, 2024Geminid Meteors: One of the year’s best meteor showers, the Geminids peak on the night of December 13 and early morning hours of December 14, 2021, but will be visible from December 4-20.

December 22/23, 2024Ursid Meteors: Catch the shooting stars of the last major meteor shower of the year, the Ursids, when it peaks between the night of December 22 and 23.

Illustration image

The Ursid meteor shower peaks at the end of December.


History of December

In the old Roman calendar, December was called mensis december, the tenth month, because the Roman calendar started in March. December initially had 29 days.

In 154 BCE, a rebellion forced the Roman senate to change the beginning of the civil year from March to January 1. With this reform, December officially became the twelfth month in the year 153 BCE.

In the year 46 BCE, Julius Caesar introduced a new calendar system—the Julian calendar. He added ten days to the year and introduced the leap day. In the new Julian calendar, December was expanded to 31 days.

Historical Events in December

December 14, 1962 – First contact with another planet. The American space probe Mariner II traveled 107 days until it passed Venus—at only 34,773 km (21,607 mi) distance. Mariner II sent back measurements of Venus’ atmosphere and temperature on the planet’s surface.

Venus captured by NASA's Mariner 10 spacecraft

Venus captured by NASA’s Mariner 10 spacecraft.


December Birthstone and Birth Flowers

According to tradition, the birthstones for December are the turquoise, the zircon, and the tanzanite. Its birth flowers are the holly and the narcissus.

Zodiac Signs in December

Topics: December, Months