Monday, 24 July 2017

Gregorian Calendar's Leap Year versus Chinese Lunisolar calendar's Leap Month

23 July 2017
Sunday

闰月
闰六月
初一

Day       Month       Year
辛    丁    丁
亥    未    酉

Gregorian Calendar (western international calendar)

Every 4 years is a leap year, with a leap day, February 29 added to the month of February. The earth rotates around the sun in 365.25 days approximately (the solar, tropical or astronomical year), and not consistently so every year also. The Gregorian calendar uses 365 days. In a leap year, an additional day is added if not the calendar will eventually have the seasonal markers like the equinox and solstice in the following month as the years go by. A day also works on the 24 hour system all through the year. 

Chinese Lunisolar Calendar 

There are two components to the Chinese calendar system, one being the lunar (moon) and the other being the solar (sun), hence the lunisolar calendar name. (side note: it is the yin-yang theory being consistent, you can't have one without the other. If there is yin, there will be a yang, vice versa duality). The lunisolar calendar as a combination calendar of both the lunar and solar calendars is also named as the Chinese Farmer's calendar. The need to combine both calendars arise from the fact that both methods (as with any calendar in the world) needs to reconcile differences as the earth and moon orbits do not necessarily fit into the 365 days a year model.

Chinese Lunar Calendar
About once every 3 years, there is a leap year where there are 13 months instead of 12 months (lunar aspect). On the calendar it is indicated with the word 闰, and 2017 is a leap year with 2 lunar 6th months. 23 July 2017 is the beginning of the second leap lunar 6th month.

Chinese Solar Calendar
The solar calendar part of the Chinese Lunisolar calendar is similar to the Gregorian in that it is based on the earth's orbit around the sun, but the actual mechanisms of naming and calculations are different. The Solar Term months do not necessarily start or end on the 12 midnight 24 hour day system. It supplements the original Lunar calendar to make the Chinese calendar system a lunisolar calendar system.


Graphics courtesy of : Jave Wu‎ / Taoist Deities & Taoist Culture Group (道教神明文化交流站) who has kindly allowed all to share.




We have crossed the Zhong Qi of the 6th solar month (22 July 2017) and are moving into the second half of the year with the Solar Term of Li Qiu (Autumn Begins) starting on 7 August 2017. 









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