eli5. New Year and Earth revolution

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Earth celebrates several new years— according to the communities and cultures. Chinese have their own new year, westerns have their own, and so have the south asian like Nepal. I’m from Nepal, and there January 1 is not the equivalent date when we celebrate our New Year. And, that might be the case for other places too(Not sure about that tho).

So, which new year is the exact day when the Earth completed one revolution around the Sun?

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10 Answers

Anonymous 0 Comments

There’s no designated starting place for one orbit so there’s no official date, either. Every day marks the end of one orbit, the one that started a year ago.

Anonymous 0 Comments

Basically all of them. When a year starts is absolutely arbitrary — you choose a day and call that the day the year starts, and then you count 365 days from that.

It’s a bit more complex than that — you have to account for leap-time, etc, but basically there’s no “correct” first day of the year.

Anonymous 0 Comments

> So, which new year is the exact day when the Earth completed one revolution around the Sun?

…They all are. They just start and end at different times along the cycle. It is a big loop, there is no objectively correct start and end point.

Anonymous 0 Comments

There’s no fixed starting point for an orbit. Each of those new years celebrates 1 revolution since the last one of that type of new years. There’s 1 revolution between Chinese new years, 1 revolution between Nepalese new years, 1 revolution between Western new years, and so on.

To put this in more concrete terms: from March 1 to March 1 is one year, from April 19 to April 19 is 1 year, from December 12 to December 12 is one year, and so on.

Anonymous 0 Comments

The other comments have already explained that you can start a revolution around the Sun on any day.

I went ahead and looked up the Nepalese calendar, which I have no prior knowledge of, and a brief glance tells me that it’s a lunisolar calendar…based on the phases of the Moon. The Moon has nothing at all to do with the Earth’s year, so generally speaking, lunisolar calendars are not a very good way of keeping track of Earth’s orbit around the Sun. There are leap years and intercalary periods to make up for this, so over long periods it isn’t an inaccurate calendar, but from one average New Year’s Day to the next, your calendar doesn’t sound like it’s a full trip around the Sun. The Gregorian calendar technically isn’t either, but it gets as close as the Earth’s rotation allows.

Anonymous 0 Comments

>So, which new year is the exact day when the Earth completed one revolution around the Sun?

There is no such objective date, because there’s no objective start or end point for what constitutes one revolution around the Sun.

*Technically* speaking, though; lunar calendars are not accurate with respect to timing the passage of a single year, entirely because they’re based on the phases of the moon. Granted, the moon actually does (by coincidence) line up relatively closely with the time it takes for the Earth to make a revolution around the Sun, but it’s going to be off, and the error builds up over time.

The Western Gregorian calendar also isn’t exact (as it tries to align travel time around the Sun to a specific number of days), but it’s much closer, and it already has a system in place called Leap Years to account for the errors.

Anonymous 0 Comments

The “New Year” is arbitrary. A year is completed when the Earth completes one revolution. That one revolution could start and complete at ANY one point.

Anonymous 0 Comments

Some calendars are lunar calendars, the Chinese year is based on the moon cycle. So the ‘new year’ date moves around. It’s Jan 23 on the western calendar, last year it was Feb 1st.

Anonymous 0 Comments

From the discontinued Julian calendar, that was eventually reformed into the modern Gregorian calendar, Janus (for which January is named after) is known as the god of gateways and beginnings.

The way we mark time is a human construct by our natrual observations. We mark the days by the earths rotation, the months or “moon’ths” by the full moons. But there is no observable marker that is dominant when the moon’ths repeat. Some cultures who didn’t have an established calendar may have marked the years by winters or summers. If there was dominant star or constellation to mark the year, then the different calendars may have used that arbitrary point to sync up the mark of the new year. Who knows, if the stars in Orion were noticeable brighter than most others, we could have called it Orions instead of years.

Anonymous 0 Comments

Persian new year (Nowruz), celebrated in Iran and some other countries is worthy to have in mind, as it is more taking into account natural and solar cycles. It is on 20 March (around equinox, when the day length supersedes the night), and signalizes the beginning of the Spring. Yalda, another celebration of theirs, is exactly on the winter solstice, the longest night in the year.