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2006-07-06 05:55:01 · 15 answers · asked by blade 2 in Science & Mathematics Mathematics

15 answers

The earth takes about 365.224 days to revolve around the sun. If one wishes the seasons of the year to start at the same time each year, then the calendrical year must have this number of days. But it's awkward to deal with the fraction, so the fix has always been to pick an integer for the number of days (usually 365), and add days (called intercalary days) from time to time to keep things from getting out of whack. Since 0.224 days is about a quarter day, an earlier calendar (the Julian calendar) threw in one extra day (leap year day) every four years; this system lasted some 1500 years. But by the sixteenth century, the accumulated error had got large enough (about 11 days) that a fix was needed, and about 1582 the scheme was revised to omit adding intercalary days in century years (1700, 1800, etc.) unless the year number was divisible by 400. (Hence, the year 2000 was a leap year but 2100 will not be.) This is the Gregorian calendar, used in most of the world today; it will have an error of about one day in 3300 years.
In Muslim countries, the Hegira calendar is used; it is based on the phases of the moon. Since twelve lunations take about 354 days, in this calendar the seasons are not constant but rotate about three times per century.
Many other calendars have been used, and some (such as the Chinese calendar) still are. Much more could be said about this, and has been, see e.g. Reingold and Dershowitz, Calendrical Calculations.

2006-07-06 06:54:19 · answer #1 · answered by Anonymous · 1 0

Actually it is the time that it takes out planet to make one complete orbit around the SUN. The actual time is said to be 365 1/4 days, which is why we have leap year every 4 years.

2006-07-06 05:58:53 · answer #2 · answered by Anonymous · 0 0

thats how about how long it takes for one revolution around the sun (or in other words, how long it takes to complete its orbit)... it really takes about a 1/4 of a day longer than 365, which is why there is a leap year every 4 years

2006-07-06 07:28:57 · answer #3 · answered by Anonymous · 0 0

It's the time it takes Earth to make a complet turn around the Sun. Except for bissextile years, that have one more day...

2006-07-06 06:01:15 · answer #4 · answered by Pedro ST 4 · 0 0

Because that is how many times the sun rises in the same amount of time it takes the earth to go once around the sun.

2006-07-06 05:57:52 · answer #5 · answered by tbolling2 4 · 0 0

A year = one rotation around the sun. For earth it take 365 days.

2006-07-06 05:59:09 · answer #6 · answered by El Griton 4 · 0 0

when you calculate in regards to earth's Rotations every day and then to complete orbit that's how long it takes.

if it was 299 days you prolly wonder the same thing....
just like why is a minute only 60 seconds or an hour 60 minutes.

2006-07-06 05:58:58 · answer #7 · answered by Oracle 3 · 0 0

it's like the first friend said also id like to add that the ancient Egyptians was the first to calculate it the made the year of 12 equal months every month 30 days
they found the have 5 more days they called them forgotten days

2006-07-06 06:04:06 · answer #8 · answered by ahmed t 1 · 0 0

Because that is how long it takes for the earth to go around the sun.

2006-07-06 05:59:31 · answer #9 · answered by Anonymous · 0 0

Because that's how long it takes our planet to make one full orbit around the Sun

2006-07-06 05:57:33 · answer #10 · answered by mom1025 5 · 0 0

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