digplanet beta 1: Athena
Share digplanet:


Applied sciences






















A lunar calendar is a calendar that is based on cycles of the lunar phases. Because there are slightly more than twelve lunations (synodic months) in a solar year, the period of 12 lunar months (354.37 days) is sometimes referred to as a lunar year.

A common purely lunar calendar is the Islamic calendar or Hijri Qamari calendar. A feature of the Islamic calendar is that a year is always 12 months, so the months are not linked with the seasons and drift each solar year by 11 to 12 days. It comes back to the position it had in relation to the solar year approximately every 33 Islamic years. It is used mainly for religious purposes, but in Saudi Arabia it is the official calendar. Other lunar calendars often include extra months added occasionally to synchronize it with the solar calendar.

The oldest known lunar calendar was found in Scotland; it dates back to around 8000 BC.[1]

Lunisolar calendars[edit]

Main article: Lunisolar calendar

Most calendars referred to as "lunar" calendars are in fact lunisolar calendars. That is, months reflect the lunar cycle, but then intercalary months (e.g. "second Adar" in the Hebrew calendar) are added to bring the calendar year into synchronisation with the solar year. Some examples are the Chinese and Hindu calendars. Some other calendar systems used in antiquity were also lunisolar.

All these calendars have a variable number of months in a year. The reason for this is that a solar year is not equal in length to an exact number of lunations, so without the addition of intercalary months the seasons would drift each year. To synchronise the year, a thirteen-month year is needed every two or three years.

Some lunar calendars are calibrated by annual natural events which are affected by lunar cycles as well as the solar cycle. An example of this is the lunar calendar of the Banks Islands, which includes three months in which the edible palolo worm mass on the beaches. These events occur at the last quarter of the lunar month, as the reproductive cycle of the palolos is synchronised with the moon.[2]

Even though the Gregorian calendar is in common and legal use, lunar and lunisolar calendars serve to determine traditional holidays in many parts of the world, including India, China, Korea, Japan, Vietnam and Nepal. Such holidays include Ramadan, Diwali, Chinese New Year, Tết (Vietnamese New Year), Mid-Autumn Festival/Chuseok and Nepal Sambat and Mongolian New Year as called Tsagaan sar.

Start of the lunar month[edit]

Lunar and lunisolar calendars differ as to which day is the first day of the month. In some lunisolar calendars, such as the Chinese calendar, the first day of a month is the day when an astronomical new moon occurs in a particular time zone. In others, such as some Hindu calendars, each month begins on the day after the full moon or the new moon. Others were based in the past on the first sighting of a lunar crescent, such as the Hebrew calendar.

Length of the lunar month[edit]

The length of each lunar cycle varies slightly from the average value. In addition, observations are subject to uncertainty and weather conditions. Thus to avoid uncertainty about the calendar, there have been attempts to create fixed arithmetical rules to determine the start of each calendar month.

The average length of the synodic month is 29.530589 days. Thus it is convenient if months are in general alternately 29 and 30 days (sometimes termed respectively hollow and full). The distribution of hollow and full months can be determined using continued fractions, and examining successive approximations for the length of the month in terms of fractions of a day. In the list below, after the number of days listed in the numerator, an integer number of months as listed in the denominator have been completed:

29 / 1 ( 1 day after about 2 months)
30 / 1 ( 1 day after about 2 months)
59 / 2 ( 1 day after about 2.6 years)
443 / 15 ( 1 day after about 30 years)
502 / 17 ( 1 day after about 70 years)
945 / 32 ( 1 day after about 122 years; expressible exactly in binary: 11101.10001₂)
1447 / 49 ( 1 day after about 3 millennia)
25101 / 850 ( dependent on change of synodic month value)

These fractions can be used to construct a lunar calendar, or in combination with a solar calendar to produce a lunisolar calendar. A 49-month cycle was proposed as the basis of an alternative Easter computation by Isaac Newton around 1700.[3] The tabular Islamic calendar's 360-month cycle is equivalent to 24×15 months minus a correction of one day.

See also[edit]


  1. ^ http://phys.org/news/2013-07-scotland-lunar-calendar-stone-age-rethink.html
  2. ^ R.H.Codrington. The Melanesians: Their anthropology and folklore (1891) Oxford, Clarendon Press
  3. ^ Reform of the Julian Calendar as Envisioned by Isaac Newton by Ari Belenkiy and Eduardo Vila Echagüe (pdf); Notes and Records of the Royal Society of London (vol 59, no 3, pp. 223-254).

External links[edit]

Original courtesy of Wikipedia: http://en.wikipedia.org/wiki/Lunar_calendar — Please support Wikipedia.
This page uses Creative Commons Licensed content from Wikipedia. A portion of the proceeds from advertising on Digplanet goes to supporting Wikipedia.
214191 videos foundNext > 



Lunar Calendar Wrong/144%

Scriptures say it is wrong. Read along with me. http://www.sacred-texts.com/bib/jub/jub20.htm http://quod.lib.umich.edu/k/kjv/browse.html.

Teach Astronomy - Solar and Lunar Calendars

http://www.teachastronomy.com/ The fundamental issue of calendars comes down to two astronomical numbers. One is the solar year, the time it takes the Earth ...

Hello China - Chinese Lunar Calendar

A selection of 100 Chinese words that represent the essence of traditional Chinese culture, reflect its extensive and profound nature from different angles, ...

Q&A: Solar, Lunar Calendar... Are We Keeping the Right Sabbath Day?

Darrio Taylor answers Reinet's question: "What do you think about the solar lunar calendar teaching? Do we worship on the wrong Sabbath day?" ONLY APPROPRIAT...

Civilization 2.8 - The Lunar/Solar Calendar

http://www.drdavidneiman.com. The Babylonians developed a calendar based on the the moon and the sun cycles. The Lunar calendar was designed to work in conju...

Moon Calendar 2013, Lunar Phases

Time lapse animation of the Moon's phases throughout the year 2013. Based on images from the Lunar Reconnaissance Orbiter. http://www.youtube.com/watch?v=Iqh...


This video takes an esoteric look at our calendar system and the possibility of life from Mars and it's association with the number of the beast 666 "Here is...

Chinese Gender Prediction Chart Explained! + How To Get Your Lunar Age!

Lunar Age Calculator: http://www.chinesegenderchart.info/gender-calculator.php Lunar Month of Conception Calculator: http://www.mandarintools.com/calconv_old...

Lunar Calendar Wine Tasting

www.thewineryuk.com - David Motion (The Winery, London), Jamie Goode (wineanorak.com) and Pierpaolo Petrassi (Tesco) interviewed on Sky News about whether wi...

214191 videos foundNext > 

208 news items

Huffington Post UK

Huffington Post UK
Thu, 14 Aug 2014 08:10:16 -0700

The spectacular sight of Qiantang River Tide usually falls on the 18th day of the eighth month in the Chinese lunar calendar. This year, affected by the supermoon, the tide came with strong bores and even injured spectators after surging over the bank.
Thu, 28 Aug 2014 22:37:30 -0700

The festival is celebrated on the 15th day of the 8th month of the lunar calendar, the Moon Festival is timed to coincide with a full moon. Its roots date back centuries, and while it is thought to have begun in conjunction with the harvest, over time ...
The Reporter
Sat, 23 Aug 2014 23:00:00 -0700

If it seems like the festival is earlier than usual this year, that's because of the Hindu lunar calendar. Tradition dictates that the festival of Ganesha — the portly, sweets-loving, elephant-headed god of good luck, wisdom and removal of obstacles ...

The News on Sunday

The News on Sunday
Sat, 30 Aug 2014 15:41:15 -0700

... attempt at a 'Pakistani IPL' was announced after the first one fell flat on its face, the arithmetic formula to calculate days in hand was no different from what it was till last Monday, unless someone had calculated number of days based on the ...
Sat, 30 Aug 2014 04:37:30 -0700

KATHMANDU, Aug 30: Hindu women across the country observed the Rishi Panchami festival as per the established rituals. The festival is observed on the fifth day of bright half-moon day of Bhadra in the lunar calendar. Hindu women reaching their ...
Tue, 12 Aug 2014 11:00:00 -0700

The lunar calendar is based on observations of the moon. The first day of each lunar month is a new moon and the 15th day is the full moon.) I've written about the hungry ghosts in previous years, more as an anthropologist, to show how even the most ...


Fri, 29 Aug 2014 08:11:15 -0700

The festival usually falls between 19 August and 20 September every year depending on the moon's movement as per the Indian lunar calendar. Mythology says rice balls are the favorite dish of Lord Ganesha and so these rice balls along with other ...

TTR Weekly

TTR Weekly
Thu, 28 Aug 2014 00:41:15 -0700

Hosted, either in September, or October, depending on the lunar calendar, the festival celebrates the Chinese belief that abstinence from meat, sex, alcohol, and other vices during the ninth lunar month of the Chinese calendar will help people to ...

Oops, we seem to be having trouble contacting Twitter

Talk About Lunar calendar

You can talk about Lunar calendar with people all over the world in our discussions.

Support Wikipedia

A portion of the proceeds from advertising on Digplanet goes to supporting Wikipedia. Please add your support for Wikipedia!