(WKBN) – Why is Christmas celebrated on December 25? It’s a date that is not entirely agreed upon by everyone.

The holiday celebrating Jesus’ birth is commonly recognized as December 25 in the Gregorian calendar, but no one knows on which date Jesus was actually born, according to Britannica.

The Roman Empire, before it recognized Christianity, celebrated the rebirth of Sol Invictus on December 25, which coincided with the Roman festival Saturnalia when people feasted and exchanged gifts.

Under Constantine, the Church in Rome began celebrating Christmas on December 25 in 336. Some say the date was chosen to outshine the Sol Invictus and pagan celebrations.

But there was a battle with Jan. 6, because that was the date the Eastern Empire celebrated Christmas.

Soon, December 25 became the preferred date to celebrate Christmas even though the Bible does not mention Jesus’ exact birthday. There are arguments about shepherds and sheep in the field signaling a spring birth, but church officials settled on December 25 at the end of the third century.

Christmas took a backseat with the Puritans in New England, seeing it as a British custom, and it became unpopular for a while following the American Revolution.

In 1870, Christmas became a federal holiday, along with New Year’s Day, Thanksgiving Day and Christmas Day — on December 25.