Significance of a year?

Question

Aside from the fact that 365 days is how long the earth takes to make a full orbit around the sun, why is it considered a year? Is there any significance to 365? Why not just say 100 days is a year?

If anyone read the question, I was not asking the signifiance of 365 nor was I asking why 365 was used. As stated in my question, I know those.

Answer 1

the number of days per year is a concequence of the length of the day and the length of the year. the spin of the earth is slowing down because of tidal effects mostly from the moon so the length of the day is getting longer so the number of days per year is getting less. some 400 000 000 years ago, in the devonian period, the day was an hour or two shorter so there were 400 days per year. earlier, in the cambrian, there were 412 days per year. in the precambrian, there were 437 days per year.

read this:
http://en.wikipedia.org/wiki/Tidal_locking#Mechanism

Answer 2

While originally the year was defined by the seasons, i.e. each time a winter came was the next year. Now a year is defined relative the stars. Each time the Earth reaches the same exact point in its orbit, the stars have the exact same angles relative to the sun. This is called the sidereal year. Since the positions of stars and the sun in the sky can be measured very precisely, the year can be measured precisely too. It is 365.25636042 days long. 365 is the rounded number used in the calendars, and to account for the extra fractions leap days are used.

Answer 3

Earth turns around 365 times

Answer 4

"Is there any significance to 365? Why not just say 100 days is a year?"

We say there are 365 because the are, in fact, about 365 days in a year, where a "day" is defined as one full rotation of Earth, and a "year" is defined as one full revolution about the sun. The number is simply the ratio of rotations per revolution. (The ratio is actually closer to 365.25, of course, hence every 4th year is a leap year.)

Answer 5

The ancients who watched the sky determend that the skys repeated themselves every 365 sun rises. This also was the same cycle as the seasons and other natural events that occur regularly. So they figured that there must be something to it, i.e. a "year".

Once they determined the cosmic cycle was 365 days, they divided it into 12 or so "months" to match the repeating cycle of the moon (28.xx days).

Then the rulers (kings, Caesers etc.) got into the picture and named these months and made them different lengths (Example August is for the roman Caesar Augustus).

Answer 6

The earth takes approximately 365.25 days to orbit the sun, and that's why a year is 365 days (excdept for leap years, which are 366). There's no other significance to the number.

Answer 7

Because they named the period that the Earth takes to orbit the Sun a "year". But they didn't know that yet. They named it that way because a year was the time it took for the four seasons to pass. And originally they didn't even name it a year! The Native Americans named them "winters", because winter came once a year.

No, there is no other significance to 365.

Answer 8

365 is used because of the sun movements around the earth. All time is based in some way or another to astrological events.

Answer 9

if you were to say 100=year all you would be doing is changing the def of the word year.

for earth, a year has to equal 365.25 days. (or 365 for 3 years and 366 for one.) becasue 365.25 is how long it takes to get around the sun. a year.

Answer 10

It is the time required to get to the same point in a season.

If the earth's axis was perpendicular to the plane of the elliptic there would be no concept of a year.