It’s only a New Year because they say it is that then; the Year should be said to have started at the Solstice, but the Julian calendar had 30 days, & Pope Gregory XI, who was rebooting it, used it as a template so the months still had 30 (or so) days. I don’t know that if the months had 28 days like the Lunar cycle then the year would end at the Solstice or not. The Solstice is not an event that begins & ends at certain times, it’s when we are going through the part of the Earth’s revolution around Sol where Earth is rounding the bend of the elliptical path it’s following; the angle of Earth’s axis of rotation relative to the plane of the ellipse remains the same, Earth doesn’t start tilting back the other way, she’s just changing position so that the angle of the axis relative to Sol changes. But in the Industrial Age, when they divided everything, including Time, into separate, discrete mechanical units that can be easily kept track of, the end of that year was then, & the start of this year is now, like someone threw a switch, that year off, this year on. At this arbitrary date. Technically, every day is the start of a new year, is it not? I like to count down the WAIT/WALK signals & cheer when they get to zero.