Does it make sense to celebrate the new year at the start of winter?

Some cultures do have their new year in springtime. Ours doesn’t.

There is no solstice in Spring. It’s called the Equinox. Spring or Vernal Equinox:

https://en.wikipedia.org/wiki/March_equinox

Thanks for the correction

The years are based on the Julian Calendar which is a solar based calendar…365 days in a solar cycle (with one extra every 4 years). Jan 1 is considered the start of the new year, probably because of the Winter Solstice. Yes, it is still winter, but it is the point where they days in the northern hemisphere are the shortest. After the solstice, the days begin getting longer again signaling the beginning of a new cycle.

This was all set up based on being in the Northern Hemisphere which the Greeks, Romans, et al were. In the southern hemisphere the “winter solstice” is actually the longest day of the year. But since all the scientists and the majority of the people on Earth were in the Northern Hemisphere at the time, it was set. For consistency the Julian calendar is used throughout the world.

I think new year should be celebrated on one’s birthday. It should then also be a holiday (as in, a day off).

We use the Gregorian calendar. Both Julian and Gregorian are solar-based. The Gregorian corrected the leap year error.

The Jewish cakendar is lunar based, but an extra month is inserted every few years to match solar-based calendars. The Islamic calendar is also lunar-based, but they don’t make any corrections, so their holidays, including new year, slide around the solar year.

New Year’s, in Julian calendars, was celebrated on April1. It was adoption of the Gregorian that moved it to January 1.

The Russian Orthodox New Year is currently celebrated on January 14.

Winter beginning is due to astronomical events.
Ask Pope Gregory XIII about Jan 1

Time has an article on Who Chose January 1 as New Years Day?