Wednesday, December 21, marks the winter solstice, which will be the shortest day for the year in the world's northern hemisphere. History shows that the winter solstice was adapted by Christians to celebrate the birth of Jesus Christ, which is now popularly known as Christmas.

Reason for Winter Solstice

Earth's axis is titled, which is why as it revolves around the sun, it will come to a point that a part of it will get less sunlight for a few months. From September to March, the northern hemisphere gets less sunlight during the day, Vox reported. Meanwhile, for the rest of the year, the northern hemisphere will get more sunlight and the southern hemisphere gets less.

Because of this, the northern hemisphere gets the least exposure to sunlight on December 21, 22, and 23. For this year, it landed on December 21. The Earth's tilted axis as it revolves around the sun is the reason for the seasons.

The farther up north the location, the less sunlight and longer nights it will get. According to Bernie Rayno, the Chief Meteorologist at AcuWeather, the winter solstice starts when the sun's direct ray hits the point on Earth called the Tropic of Capricorn.

For 2016, the northern hemisphere will experience the winter solstice at 5.44 a.m. EST on December 21.

Evolution of Christmas from Winter Solstice

In ancient times pagans had various celebrations to honor the winter solstice, Christianity later on adopted the date and marked December 25 as the birthday of Jesus Christ, which is now known as Christmas, ABC 7 reported.

The earliest recorded Christmas celebration was in the year 336, when Constantine was the Emperor of Rome. Constantine was the first Roman Emperor who adopted Christianity. After a few years, Pope Julius I declared December 25 as the birthday of Jesus, and officially became Christmas.