Since at least the neolithic , humans have been creating calendar to keep trail of the change time of year . Secularly today , we used the Gregorian calendar introduce in 1582 by Pope Gregory XIII . This is a solar calendar , where one solar year is measured by one rotation of the Sun by Earth and is equivalent to365.2422 sidereal day . But solar calendars are not the only agency to measure prison term . With Chinese New Year yesterday , China has just entered the Year of the Rabbit , consort to the lunar calendar .
What is a lunar calendar?
Lunar calendar are base entirely on the lunar cycle . A lunar calendar month is29.5 daysso is a menstruum of 12 lunations . The standard lunar year comes unforesightful of the solar yr with 354 day and a handful of hour .
The Islamic Hijiri calendar has month that last either 29 or 30 days with each calendar month , commence at the first sight of our rude orbiter following the new Moon . The months in a lunar calendar cycle through the seasons of a solar calendar over 33 - 34 lunar years .
What are lunisolar calendars?
Other calendars have taken a hybrid approach path . Lunisolar calendar use lunar cycles to dictate the calendar month but equalize it to the solar calendar with the use of leap months every few year to make up the departure between the lunar and solar calendars .
Lunisolar calendars are used in many civilization . Some are from ancient times , used by the Inca , Babylonians , Egyptians , and Kelt . Others are still in utilisation today such as the Hebrew calendar , the calendar from the Hindu calendar phratry , and calendars descendent or mold by the traditional Chinese calendar .
Why do some religious festivals change in the calendar?
While , most countries apply the Gregorian calendar , lunar and lunisolar calendars are used to reckon religious festivities in every finish . The date of Easterfor Christians and Pesach for Jewish people reckon on the first full Moon following the northerly bound equinoctial point ( although due to leap month in the Hebrew calendar , this can interchange ) .
The month of Ramadan is the 9th in the Muslim calendar and it last from the first sight of the crescent Moon to the next . The Hindu festival of Holi is celebrated on the full Moon of the Phalgun month in the Hindu calendar .
When is Chinese New Year?
Variants of the Chinese calendar have influenced many calendars across the Sinosphere , and its most popular festivity – the Spring fete , now known as Chinese New Year – has mold the Lunar New Year jubilation for many other Asian commonwealth and culture . It falls onthe new Moon , during a stop that in the Gregorian calendar is between January 21 and February 20 .
