Lunar Calendar Definition

What is a lunar calendar? A lunar calendar is a calendar that is based on cycles of the moon phases. Lunar calendars have been used since ancient times. Evidence of lunar calendars dates back as far as 32,000 years ago. Some artifacts from the Ice Age include sticks, reindeer bones and mammoth tusks with marks that academic scholars believe depict the days between moon phases.

The most common purely lunar calendar is the Islamic calendar. A feature of the Islamic lunar 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. The lunar calendar comes back to the position it had in relation to the solar year approximately every 33 Islamic years. This lunar calendar is used mainly for religious purposes, and in Saudi Arabia it is also used for commercial purposes. Because there are about twelve lunations in a solar year, this period (354.37 days) is sometimes referred to as a lunar year.

Lunar Calendar Examples

Some of the most common lunar calendars are examples are as follows:
  • Islamic Lunar Calendar. The only purely lunar calendar widely used today is the Islamic calendar, called the Hijri calendar. The years always have 12 lunar months. Because of the varying length of these lunar months, this calendar can’t be linked to the seasons. While the Hijri calendar is the official calendar in countries around the Gulf, including Saudi Arabia, other Muslim countries only use the Islamic calendar for religions purposes and use the Gregorian calendar for civil purposes.
  • Mayan Lunar Calendar. The Mayan Calendar was a lunar calendar system based on the agriculture requirements of living in a rain forest. The Mayans invented numerous calendar systems, but the most important one was the sacred tzolkin. This lunar calendar was made up of 260 days and had two repeating cycles. One cycle consisted of 13 numbered days and the other cycle was made up of 20 named days.
  • Babylonian Lunar Calendar. The Babylonian lunar calendar consisted of 12 months that alternated between being 29 days and 30 days long. Months with 29 days were called “hollow,” while those with 30 days were called “full.” This calendar was used for over 3000 years, not falling out of favor until about 238 BCE.
  • Chinese Lunar Calendar. The Chinese originally used a lunar calendar system to determine the best times to plant, harvest, and hold their many religious festivals. Though a majority of modern Chinese citizens use the Western solar calendar for the more practical matters of their everyday lives, the old lunar calendar is still used to determine the dates of holidays and festival occasions. The Chinese people have long accepted this coexistence of two different calendar systems.

Start of the Lunar Calendar Month

Lunar Calendar

Lunar Calendar

Lunar calendars differ as to which day is the first day of the month. For some lunar 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. For 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 Calendar

The average length of the synodic month is 29.530589 days. This requires the length of a month to be alternately 29 and 30 days (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 (error: 1 day after about 2 months)
  • 30 / 1 (error: 1 day after about 2 months)
  • 59 / 2 (error: 1 day after about 33 months)
  • 443 / 15 (error: 1 day after about 30 years)
  • 502 / 17 (error: 1 day after about 70 years)
  • 1447 / 49 (error: 1 day after about 3 millennia)
  • 25101 / 850 (error: dependent on change of synodic month value)
  • The following fraction is used in the Hebrew calendar: 765433 / 25920 (error: 1 day after about 16 millennia)

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

Lunar Calendar 2016

The lunar calendar for 2016 is expressed in Coordinated Universal Time (UT), the international basis for other time zones. Astronomers call one lunar cycle a lunation. For lunar calendar times in your city, please use the Time Zone Converter. You can also simply subtract five (5) hours to get to U.S. Eastern Time.

New MoonFirst Quarter MoonFull MoonLast Quarter Moon
Dec 3 – 07:40
Dec 11 – 10:29Dec 18 – 15:14Dec 25 – 11:11Jan 2 – 05:30
Jan 10 – 01:30Jan 16 – 23:26Jan 24 – 01:46Feb 1 – 03:28
Feb 8 – 14:39Feb 15 – 07:46Feb 22 – 18:20Mar 1 – 23:11
Mar 9 – 01:54Mar 15 – 17:03Mar 23 – 12:01Mar 31 – 15:17
Apr 7 – 11:24Apr 14 – 03:59Apr 22 – 05:24Apr 30 – 03:29
May 6 – 19:30May 13 – 17:02May 21 – 21:15May 29 – 12:12
Jun 5 – 03:00Jun 12 – 08:10Jun 20 – 11:02Jun 27 – 18:19
Jul 4 – 11:01Jul 12 – 00:52Jul 19 – 22:57Jul 26 – 23:00
Aug 2 – 20:45Aug 10 – 18:21Aug 18 – 09:27Aug 25 – 03:41
Sep 1 – 09:03Sep 9 – 11:49Sep 16 – 19:05Sep 23 – 09:56
Oct 1 – 00:12Oct 9 – 04:33Oct 16 – 04:23Oct 22 – 19:14
Oct 30 – 17:38Nov 7 – 19:51Nov 14 – 13:52Nov 21 – 08:33
Nov 29 – 12:18Dec 7 – 09:03Dec 14 – 00:05Dec 21 – 01:56
Dec 29 – 06:53

Lunisolar Calendar

Most lunar calendars are in fact lunisolar calendars. That is, months reflect the lunar cycle, but then intercalary months are added to bring the calendar year into synchronisation with the solar year. Some examples are the Chinese and Hindu calendars, and most calendar systems used in antiquity.

All these calendars have a variable number of months in a year. The reason for this is that a year is not evenly divisible by an exact number of lunations, so without the addition of intercalary months the seasons would drift each year. This results in a thirteen-month year every two or three years. Even though the Gregorian calendar is in common and legal use, lunar calendars serve to determine traditional holidays in parts of the world such as China, Korea, Japan, and Vietnam.

Lunar Eclipse Calendar

The lunar eclipse calendar is a listing of all lunar eclipses from 2016 through 2018. Times are expressed in Coordinated Universal Time (UT), the international basis for other time zones. You can also simply subtract five (5) hours to get to U.S. Eastern Time. The type and length of a lunar eclipse depends upon the Moon’s location relative to its orbital nodes. A lunar eclipse lasts for a few hours and can be viewed from anyone on the night side of the Earth. For additional lunar eclipse dates, please see NASA’s lunar eclipse page.

Solar EclipseTotal2016Mar 8/9South/East Asia, North/West Australia, Pacific, Indian Ocean
Lunar EclipsePenumbral2016Mar 23Much of Asia, Australia, North America, Much of South America, Pacific, Atlantic, Indian Ocean, Arctic, Antarctica
Solar EclipseAnnular2016Sep 1South in Asia, West in Australia, Much of Africa, Atlantic, Indian Ocean, Antarctica
Lunar EclipsePenumbral2016Sep 16/17Europe, Asia, Australia, Africa, West in South America, Pacific, Atlantic, Indian Ocean, Arctic, Antarctica
Lunar EclipsePenumbral2017Feb 10/11Europe, Much of Asia, Africa, North America, South America, Pacific, Atlantic, Indian Ocean, Arctic, Antarctica
Solar EclipseAnnular2017Feb 26South/West Africa, Much of South America, Pacific, Atlantic, Indian Ocean, Antarctica
Lunar EclipsePartial2017Aug 7/8Much of Europe, Much of Asia, Australia, Africa, West in South America, Pacific, Atlantic, Indian Ocean, Antarctica
Solar EclipseTotal2017Aug 21West in Europe, North/East Asia, North/West Africa, North America, North/West South America, Pacific, Atlantic, Arctic
Lunar EclipseTotal2018Jan 31North/East Europe, Asia, Australia, North/East Africa, North America, North/East South America, Pacific, Atlantic, Indian Ocean, Arctic, Antarctica
Solar EclipsePartial2018Feb 15South in South America, Pacific, Atlantic, Antarctica
Solar EclipsePartial2018Jul 13South in South America, Pacific, Atlantic, Antarctica
Lunar EclipseTotal2018Jul 27/28Much of Europe, Much of Asia, Australia, Africa, South in North America, South America, Pacific, Atlantic, Indian Ocean, Antarctica
Solar EclipsePartial2018Aug 11North/East Europe, North/West Asia, North in North America, Atlantic, Arctic

Lunar Eclipse Cycle

Every year there are at least two lunar eclipses, although total lunar eclipses are significantly less common. If one knows the date and time of an eclipse, it is possible to predict the occurrence of other eclipses using an eclipse cycle like the saros.

Lunar Eclipse Mythology

Several cultures have myths related to the lunar eclipse. The Egyptians saw the eclipse as a sow swallowing the moon for a short time. Other cultures viewed the eclipse as the moon being swallowed by other animals, such as a jaguar in Mayan tradition, or a three legged toad in China. Some societies thought it was a demon swallowing the moon, and that they could chase it away by throwing stones and curses at it.

Popular Full Moon Calendars

Some popular full moon calendars, in addition to the 2016 Full Moon Calendar, include the following: Moon Calendar 2011, Moon Calendar 2012, Moon Calendar 2013, Moon Calendar 2014, Moon Calendar 2015, Moon Calendar 2016, Moon Calendar 2017, Moon Calendar 2018, Moon Calendar 2019, Moon Calendar 2020.

You can also check out our Full Moon Calendar, Lunar Calendar, Lunar Eclipse Calendar and Solar Eclipse Calendar!