Apart from the old "folklore" of being able to ask a man to marry you (yipee) when it's a leap year, what purpose do they serve and how did it originate?
2007-02-28 04:16:46 · 14 answers · asked by long_luscious_lashes 3 in Society & Culture ➔ Mythology & Folklore
we have a leap year as a standard year is counted as 365 days when in fact it takes the Earth 365 and 1/4 days to orbit the sun so once every 4 years we have a leap year to keep the days/weeks/months & seasons in the right place at the right time throughout the year.
2007-02-28 04:23:26 · answer #1 · answered by Cruz 4 · 2⤊ 0⤋
Leap years are needed so that the calendar is in alignment with the earth's motion around the sun.
The Gregorian calendar, the current standard calendar in most of the world, adds a 29th day to February in all years evenly divisible by 4, except for centennial years (those ending in -00), which receive the extra day only if they are evenly divisible by 400. Thus 1600, 2000 and 2400 are leap years but 1700, 1800, 1900 and 2100 are not.
The reasoning behind this rule is as follows:
The Gregorian calendar is designed to keep the vernal equinox on or close to March 21, so that the date of Easter (celebrated on the Sunday after the 14th day of the Moon that falls on or after 21 March) remains correct with respect to the vernal equinox. [citation needed]
The vernal equinox year is currently about 365.242375 days long.
The Gregorian leap year rule gives an average year length of 365.2425 days.
This difference of a little over 0.0001 days means that in around 8,000 years, the calendar will be about one day behind where it should be. But in 8,000 years, the length of the vernal equinox year will have changed by an amount which can not be accurately predicted. Therefore, the current Gregorian calendar suffices for practical purposes.
The Julian calendar had introduced too many leap days, so that vernal equinox did no longer happen around March 21, as it did back in AD 325 during the Council of Nicaea. The introduction of the Gregorian calendar should realign the calendar with the equinox, so a number of days had to be dropped when going from the Julian to the Gregorian calendar.
The Gregorian calendar was first adopted in Italy, Poland, Portugal and Spain in 1582. This was done by dropping 10 days in October (Ottobre).
In Great Britain (and to-become USA), the Gregorian calendar was adopted much later - 11 days were dropped in September 1752.
Sweden (and Finland) had a "double" leap year in 1712 - two days were added to February, so that there was a date February 30, 1712. (This was done because the leap year in 1700 was dropped and Sweden's calendar was not synchronized with any other calendar - by adding an extra day in 1712, they were back on the Julian calendar).
The old Julian calendar is currently (between year 1901-2099) 13 days past the Gregorian calendar (because too many leap years were added).
The Gregorian calendar has a 400 year long cycle and the calendars have the same week days -- February 29, 2008 is a Friday and February 29, 2408 is a Friday.
The Gregorian calendar has 97 leap years during those 400 years.
The longest time between two leap years is 8 years. Last time was between 1896 and 1904. The next time will be between 2096 and 2104.
A leap year is needed in order to keep the calendar year synchronised with the astronomical or seasonal year.
Hope that helps you out.
2007-02-28 12:32:06 · answer #2 · answered by Marmylade 2 · 1⤊ 1⤋
actually any year contains 365 1/4 th days i.e. its this number of days in time that the earth takes to re3volve once around the sun...n since there can be no 1/4 the day so for 4 years the 1/4th days are added up n the product is one extra day for feb month giving us a leap year!!
2007-03-01 09:49:35 · answer #3 · answered by simplynuts 2 · 0⤊ 0⤋
Seasons and astronomical events do not repeat at an exact number of days, so a calendar which had the same number of days in each year would over time drift with respect to the event it was supposed to track.
By occasionally inserting an additional day or month into the year, the drift can be corrected.
2007-02-28 12:21:49 · answer #4 · answered by Anonymous · 1⤊ 0⤋
There are 23 hours and 56 minutes in a day. when you add all these together you come up with an extra day every 4 years. The reason there are 23 hours and 56 minutes in a day is due to the rotation of the Earth.
2007-02-28 12:31:50 · answer #5 · answered by ccourtne_99 2 · 0⤊ 0⤋
It's to make up for there being 365 1/4 days in a year.
2007-02-28 12:21:32 · answer #6 · answered by Anonymous · 3⤊ 0⤋
If it weren't for leap years, September would fall in the Spring (that's an example)
Our calendar would be screwed up.
2007-02-28 16:45:40 · answer #7 · answered by al5645al 2 · 0⤊ 0⤋
It takes the Earth 365.251 days to go around the Earth so every four years we have an extra day or else in 500 years or so, winter would be in June.
2007-02-28 12:24:39 · answer #8 · answered by closetcoon_fan 5 · 2⤊ 0⤋
there's just a hair more than twenty four hours in a day, so once
every 4 years we throw a day in there to keep the calender straight.
Ask the Romans why different months have different numbers
of days.
2007-02-28 12:30:57 · answer #9 · answered by Anonymous · 0⤊ 0⤋
So that the calendar year doesn't get too far away from the solar year. It's basically a way to catch up on time that we lose from our 24 hour day.
2007-02-28 12:25:16 · answer #10 · answered by Emo Girl 2 · 0⤊ 1⤋