Our planet spun around its access 365 times since we last celebrated New Years’ Eve. We travelled around the sun one more time.
Though the duration of our calendar system’s years are astronomically determined, the choice of day is very arbitrary. We could have chosen any other day — in fact there exist many other calendar systems with differing new years days (see New Year on Wikipedia).
If we wanted an astronomically significant day, we could have gone with summer or winter solstice (longest or shortest day of the year, but which hemisphere?), or for that matter the March or September equinox (when day and night are equally long, with the sun right above the equator). In fact, some calendars, such as the Iranian calendar, does just that: new year’s day on the vernal equinox (Spring equinox, i.e. March, northern hemisphere).
The point being: we’re talking pure human culture here, nothing more.
And yet the day carries much significance in our culture, there is no denying that — it forms a part of many people’s yearly rituals, a rhythm to life. We open champagne bottles with friends or family, we fire fireworks, we consider the year behind and the year ahead, we make new years’ resolutions, we have countdowns…
What did you do on the evening of the 31st?