Yes, for the sake of doing so. But it did not coincide with any major Pagan roman holiday.
December 23.
It was- until Charlemagne was crowned.
The idea of celebrating was from Charlemagne, who had his coronation on Dec 25, thus he could have big celebrations- ostensibly for Christ Birthday, but in reality for him.
Then of course some folk and pagan things were added in- yule logs, Christmas trees, mistletoe and what not- later.
For a very short time, before Jesus was even born, but then, it moved- but not officially, in some calendars. And it wasnt a holiday anyway. Well, not one of the big ones, there were well over a hundred Roman Holidays.
And Saturnalia, which was the BIG Holiday, wasnt on Dec 25th anyway, it was on the 17th. In fact Saturnalia was pretty much gone before the date of Christmas was calculated.
There was no pagan reason to pick Dec 25th since again, there were no celebrations on Christmas to compete with any Pagan parties, which was the idea they came up with over a thousand years later- “Hey, look, everyone is used to having a big party with gifts and feasting on Saturnalia, so lets put Christmas there, with parties and gift giving.” But that idea was wrong.
Note that there were something like 30 Feast days around that time, and like 135 to 177 Roman holidays so the chance a feast day would hit on a holiday is just about certain. So ANY date the early Christian fathers picked would be near some Roman holiday. The fact that Christmas is Dec 25, and Saturnalia is the 17th is a coincidence.
I didn’t say the 25th was the Saturnalia. It wasn’t. It was the solstice. In 274CE, Emperor Aurelian made it the festival Dies Natalis Solis Invicti. Susan Roll in Toward the Origins of Christmas. (1995 p. 107) says that liturgical historians generally accept that the winter solstice had some influence that December 25 was chosen for Christmas. But I have no expertise in these matters.
Which festival was official from 274 AD until he died- one year later. Maybe until 282, hard to tell.
Anyway, that cult went away pretty fast or went underground. In any case, Mithraism stole from Christianity, not the other way around-
And yeah, that was a hypothesis for a while-
A widely-held hypothesis is that the early Church chose December 25 as Jesus Christ’s birthday (Dies Natalis Christi) to appropriate the festival of Sol Invictus’s birthday (Dies Natalis Solis Invicti), held on the same date.[54][68][69] The Calendar of Filocalus (c.336 AD) is the earliest record of both the Natalis Invicti and Christ’s birthday being marked on December 25. Steven Hijmans argues that the earliest certain evidence for a festival of Sol Invictus on December 25 is from Julian, thirty years later; he suggests that the pagan feast might have been a reaction to the Christian one rather than vice versa.[70]
There are lots of hypothesis but all the ideas that Christmas was placed on a pagan holiday to compete with it didnt happen until 1200 years after Christ. By that time, Christmas was a real modern style holiday, with merrymaking, gifts etc.
But in any case, Dec 25 was picked for the birth of Jesus as it was nine months after easter, and the thought was the Conception occurred on the same day as Easter. This came from about the 4th century, so much earlier than any idea of it being in competition- which since Christmas wasnt celebrated with any sort of fun or merrymaking until 814AD- then it became the 12 days of Christmas. Epiphany was a bigger holiday until then. And even then Christmas wasnt really what we would think about-
Note that what we call a modern Christmas didnt occur until 1870s.