The year "dies" on the longest, darkest nights. (Dec 21, technically). We mourn its passing and celebrate it's life with drinks. I'm guessing there was in antiquity, a whole bunch of dreadful and exciting parties in the last 10 days around the longest nights.

It slowly grows after that and blooms later.

January 1 is so close to December 25 (when Jesus is believed to have been born) so if we wanted to count years since that -- and call it AD for "Anno Domini" (the Year of Our Lord) -- we could declare the year to begin on January 1st.

Which is exactly what we did.

> December 25 (when Jesus is believed to have been born)

I don't think anyone actually believes Jesus was born on Dec 25.

A lot of people believe a lot of things. I wonder why you don't believe that people believe this.

Now whether you yourself believe he was born then, another time or ever existed at all etc is another story.

I believe for example that everyone can believe whatever they want about those things as long as:

    They leave me alone when I tell them I don't believe that and I don't want to be convinced

    They don't try to kill me, enslave me, etc for being an infidel (yes that includes the Christian holy wars sort of thing but also current events)

To clarify, it is well-established that December 25 is a highly unlikely date for the birth of Jesus.

Children and people who have only a superficial knowledge of Christianity might very well believe otherwise. But they are poorly-informed.

Arguments against include:

  a) Precise calendar dates are often fuzzy from that period, so the likelihood of knowing at all is very low.
  b) The mythology around the birth date does not match the seasonal expectations for late December (more likely springtime).
  c) Dec 25 was chosen in 336 AD, by church decree. Prior to that, there was no holiday nor even a strong claim of any specific date.
  d) Dec 25 was already a festival day for pagan celebrations of Saturn (Rome) and Mithra (Persia), which was likely a factor in the choice of date, to coincide with existing customs.

There are no substantial arguments in favor of December 25 being accurate.

I don't think anyone is arguing that December 25 is the birth date of Jesus (assuming he existed), the argument is just that there are people who believe it is. You seem to think only children and people who don't know much about Christianity would believe that, but I assure you there are lots of Christian adults who don't know the history you (correctly) laid out.

The point is that the "birth date of Jesus" being set on December 25 came 350 years after January 1 was chosen to start the new year.

No the point is that my parent said:

    I don't think anyone actually believes ...

when in fact, yes, people do actually believe this.

When this is pointed out, he explains why it can't be Dec 25th and that's all totally fine and correct but doesn't change the fact that yes indeed there are people that believe that, as well as lots of other things that can easily be disproved. It does not matter whether you can disprove it to us and others. These people that do believe it are in fact out there.

January 1st became the start of the year about half a century before Jesus was born.

25 of December is close to the winter solstice (around 22nd), and I suspect it was ascribed to that day for astrological reasons; there are a few other astrological clues around that episode, most prominently, the Bethlehem Star.