Calendar of the Baha'i Faith

The Baha'i calendar, known as the Bad (which means "wonderful"), is divided into nineteen months, each with nineteen days. 

  • In normal years, four intercalary days — known as AYYAM-I-HA, or the Days of Ha — come after the eighteenth month, while five are added in leap years. 
  • The sum of 19 multiplied by 19 = 361, plus four intercalary days equals 365. 
  • However, the number nineteen was selected for reasons other than its mathematical use. 

Mirza Ali Mohammad (commonly known as the BAB), the Baha'i faith's first prophet, created a calendar for the new religion. 

He had eighteen disciples, thus the calendar's structure remembers the nineteen original Babis.


  • The regular Baha'i worship gathering is the Nineteen-Day Feast, which takes place on the first day of each month. 
  • The three-part structure of each Feast is the same: prayer, congregational business, and fellowship over a shared meal. 
  • The Baha'i year starts on March 21, the spring equinox. 
  • The years of the Baha'i faith are running out. 
  • The first year was 1844, which was the year of the Bab's Declaration. 

Each Baha'i month is named after one of God's attributes: 

Bahá (Splendor) March 21

Jalál (Glory) April 9

Jamál (Beauty) April 28

Azamat (Grandeur) May 17

Núr (Light) June 5

Rahmat (Mercy) June 24

Kalimát (Words) July 13

Kamál (Perfection) August 1

Asmá (Names) August 20

‘Izzat (Might) September 8

Mashiyyat (Will) September 27

‘Ilm (Knowledge) October 16

Qudrat (Power) November 4

Qawl (Speech) November 23

Masá’il (Questions) December 12

Sharaf (Honor) December 31

Sultán (Sovereignty) January 19

Mulk (Dominion) February 7

Ayyam-i-Ha (Days of Ha; intercalary days): February 26-March 1 (February 26-March 2
in leap years)

‘Alá’ (Loftiness) March 2 (month of fasting)

You may also want to learn more about Global Calendar Systems here.

Mayan And Aztec Calendar

Both the Mayan and Aztec civilizations utilized what is known as the Mesoamerican calendar. The Olmec civilization, which flourished between 1300 and 400 B.C. in what is now southeastern Mexico along the Gulf, may have inspired this ancient calendar. 

Between 1000 and 900 B.C., the Mesoamerican calendrical system used not just one calendar, but a system of two interconnected calendars: 

  1. a 260-day calendar and 
  2. a 365-day calendar. 

These two calendars were shown side by side. 

A named day from the 260-day calendar would be the same as a named day from the 365-day calendar once every 52 years (there are 18,980 days in 52 years, and 18,980 is the least common multiple of both 365 and 260). 

Both the Mayans and the Aztecs were aware of this 52-year cycle. 

Between 300 and 900 A.D., Mayan civilization thrived in what is now southeastern Mexico, Belize, and parts of Guatemala and Honduras, a period known as the Classical Mayan Period. 

  • The 260-day tzolkin calendar was utilized for religious reasons, while the 365-day solar-based calendar, known as the haab, was employed for agricultural purposes. 
  • The Mayan calendar system used glyphs, which are tiny graphic inscriptions, to indicate time periods such as a day, a month, and a year, as well as particular months and days within those months. 
  • Each day was named after a deity who was said to have shown himself on that particular day. 
  • The numbers for the days were written using a mix of dots and bars. 
  • The Mayan calendar was split into 13 months, each of which included 20 designated days. 
  • The 365-day calendar was split into 18 months with 20 named days each, plus a five-day month called Uayeb, which meant "ominous days." 
  • The Calendar Round is a Mayan cycle that lasts 52 years. 
  • The 260-day method is said to be the world's only one of its type. 
  • Scholars are unsure what the significance of 260 is, but some have pointed out that the typical human pregnancy lasts around 260 days. 

Furthermore, the Mayans had a sophisticated understanding of astronomy, and 260 was a significant number in calculating the appearance of Venus — the planet associated with the Mayan god Kukulcán, known to the Toltecs as Quetzalcoatl — who dominated Mesoamerica from the 10th century to the middle of the 12th century. 

  • Mayans also devised the Long Count, a complex time-keeping system that sought to cover the whole history of the planet from its beginning to its conclusion. 
  • Between 400 B.C. and 100 A.D., the Mayans are believed to have created the Long Count. 
  • They calculated that the present creation took place in 3114 B.C. using this method (or 3113 B.C., by some contemporary calculations). 
  • According to some experts, the Long Count will finish in December 2011. (or 2012). 
  • After the fall of the Toltec kingdom, the Aztecs (who called themselves Mexica) ruled Mesoamerica from the early 1300s until the Spanish started colonization in the early 1600s. 

  • The Aztecs, like the Mayans, employed a 260-day calendar split into 13 months of 20 days, which they termed tonalpohualli, or "day count." 
  • Their 365-day calendar also had 18 months of 20 days and a five-day interval that the Aztecs considered bad. 
  • The Aztecs also named their days after gods, but unlike the Mayans, they used just dots for number representation. 

  • A Long Count was most likely not used by the Aztecs. 
  • The Aztecs celebrated the new beginning with a huge renewal ritual at the conclusion of their 52-year cycle, which they termed xiuhmolpilli, or "year bundle". 
  • The 365-day civil calendar is now widely used across the area, but some Mayans still utilize the 260-day calendar to commemorate holy events.

You may also want to learn more about Global Calendar Systems here.

Chinese Calendar

The Chinese calendar, which is extensively used in Asian nations, is based on the oldest still-in-use method of time measurement, with an epoch of 2953 B.C. 

  • Part of the reason the Chinese calendar has remained intact for so long is because it was regarded holy until the middle of the twentieth century. 
  • Any modifications to the calendar were strictly regulated by imperial officials, and interfering with the time-keeping system was punishable by death. 
  • The official calendar was given to the emperor, governors, and other officials in an annual ceremony until the advent of Communism in China during the twentieth century. 
  • The Gregorian calendar has been in use for municipal purposes since 1912. 
  • The Chinese New Year occurs on the new moon closest to the point in the zodiac sign of Aquarius that is described in the West as the fifteenth degree. 
  • Each of the Chinese year's twelve months lasts twenty-nine or thirty days and is split into two halves, each lasting two weeks. 
  • The Chinese calendar, like other lunisolar calendars, has to be adjusted on a regular basis to maintain the lunar and solar cycles in sync, thus an intercalary month is added when required. 
  • Each of the twenty-four two-week periods has a name that corresponds to a festival that takes place at that time. 

These periods begin with the New Year, which occurs in late January or early February, and are referred to as: 

The Rain Water, 

the Excited Insects, 

the Vernal Equinox, 

the Clear and Bright, 

the Grain Rains, 

the Summer Begins, 

the Grain Fills, 

the Grain in Ear,

the Summer Solstice, 

the Slight Heat, 

the Great Heat, 

the Autumn Begins, 

the Heat Limit, 

the White Dew, 

the Autumnal Equinox, 

the Cold Dew, 

the Hoar Frost Descends, 

the Winter Begins, 

the Little Snow, 

the Heavy Snow, 

the Winter

You may also want to learn more about Global Calendar Systems here.

Buddhist Calendar

The Buddhist calendar, like the Hindu calendar, began in India and varies according to geographical region. Among Buddhist groups, the process for calculating the new year's date varies. 

Theravada Buddhists (mostly in Sri Lanka, Laos, Burma/Myanmar, Thailand, and Cambodia) use a Hindu calendar to calculate the months and the new year by the position of the sun in reference to the twelve segments of the sky, each named after a zodiac sign. 

  • When the sun enters Aries, which occurs between April 13th and April 18th, the solar new year starts. 
  • The duration of the lunar months alternates between twenty-nine and thirty days. 
  • Except for the Burmese Buddhist calendar, which starts in April, the first lunar month is typically in December (see Hindu Calendar above for Burmese names). 
  • Intercalary days are added to the seventh month on a regular basis, and an intercalary month is introduced every few years. 
  • The months are referred to by number in Cambodia, Laos, and Thailand. 

Tibetan Buddhists, whose calendar is strongly influenced by the Chinese calendar, start the new year on the full moon closest to Aquarius' midway. 

Mahayana Buddhists (mainly in Tibet, Mongolia, China, Korea, and Japan) follow the Buddhist, Chinese, or Gregorian calendars for their festivals.

You may also want to learn more about Global Calendar Systems here.

Hindu Calendar

Despite the fact that each geographical area of India has had its own calendar, they are all based on an ancient calendar, India's oldest time measuring system, which can be found in writings dating back to 1000 B.C. 

  • The bulk of the many regional Hindu calendars, which are solely used for religious festivals, split a solar year of 360 days into twelve months. 
  • With the intercalation of a leap month every sixty months, each day is 1/30th of a month. 
  • Along with the calendar, time measurements based on constellation sightings are utilized. 
  • Each month is split into two fortnights: 
    • krsna (dark or waning half) and 
    • sukla (light or brilliant half) (waxing or bright half). 
  • The month starts with the new moon in southern India. 
  • The full moon is marked the start of the month in other areas of the nation. 
  • Many references to the Hindu calendar are provided as follows (depending on the source): month, fortnight (either S=waxing or K=waning), and number of days in that fortnight, for example, Rama Navami: Caitra S. 9. 

The Hindu months' names (with other spellings) are shown below, with the Burmese name in brackets: 

  1. March-April: Caitra or Chaitra [Tagu] 
  2. April-May Vaisakha [Kasone] 
  3. May-June: Jyeshta or Jyaistha [Nayhone] 
  4. June-July: Ashadha or Asadha [Waso] 
  5. July-August at Sravana [Wagaung]. 
  6. Asvina [Thadingyut]: September-October 
  7. Bhadrapada [Tawthalin]: August-September 
  8. October-November: Kartika or Karttika [Tazaungmone] 
  9. November-December: Margasirsa or Margashirsha [Nadaw] 
  10. December-January: Pausa or Pausha [Pyatho]. 
  11. January-February [Tabodwei] Magha 
  12. February-March Phalguna [Tabaung]

You may also want to learn more about Global Calendar Systems here.

Islamic Calendar

The Islamic calendar, known as hijri or Hegirian, is still based only on the lunar calendar. Furthermore, the sighting of the new moon determines the start of a month. 

  • If the sky is cloudy and the new moon cannot be seen, the previous month continues for another thirty days until the new month starts. 
  • The practical start of a month, on the other hand, is determined by moon cycle astronomical calculations. 
  • The Islamic period starts on July 16, 622, with the Prophet Muhammad's hegira, or departure into exile from Mecca to Medina. 
  • There are twelve Islamic lunar months, some of which are twenty-nine days long and others which are thirty days long, giving a total of 354 days in the Islamic year. 
  • Of comparison to the Gregorian calendar, the fixed holidays in the Islamic calendar shift “backward” approximately 10 days each year. 
  • Ramadan, the Islamic holy month of fasting, travels back across the full solar year in around 36 years. The Islamic day begins at sunset and ends at sunset. 

Other calendars were created in Islamic nations for agricultural purposes, which rely on the solar calendar. 

  • The Coptic calendar, a variant of the Julian calendar, was widely used until recently, but it is currently restricted to Egypt and Sudan, two nations with significant Coptic populations. 
  • The Ottoman Empire utilized the Turkish fiscal calendar, which was likewise Julian-based. 
  • In today's world, the Gregorian calendar is used almost everywhere for civic reasons, whereas the Islamic calendar solely sets religious observance days. 
  • Saudi Arabia is an anomaly, since it utilizes the Islamic calendar as its reference calendar, at least officially. 

The Islamic month names are an old representation of the solar year's seasons: 

  1. Muharram is the holy month, whereas Safar is the empty month. 
  2. Rabi al-Awwal is the first month of the Islamic calendar. 
  3. The second spring is Rabi ath-Thani. 
  4. The first month of dryness is known as Jumada-l-Ula. 
  5. The second month of dryness is known as Jumada-th-Thaniyyah. 
  6. Rajab is regarded as a holy month. Shaban is known as the month of division. 
  7. Ramadan is the hottest month of the year. 
  8. Shawwal is the month of the hunt. 
  9. The month of Dhu al-Qadah is known as the month of repose. 
  10. The month of Dhu al-Hijjah is the month of pilgrimage.

You may also want to learn more about Global Calendar Systems here.

Jewish Calendar

Hillel II instituted a permanent calendar based on mathematical and astronomical calculations in 358, removing the necessity for eyewitness observations of the new moon, which marks the start of a new month. 

  • Due to uncertainty about the timing of the new moon, ancient law mandated that people living outside of Israel celebrate two days instead of one for each holiday, with the exception of Yom Kippur, the Day of Atonement. 
  • This tradition had to be kept even after the calendar was created, according to the Talmud. 
  • The Jewish period starts with the creation of the world, which is generally dated at 3761 B.C. Hillel's calendar has remained mostly unaltered since the eleventh century, with very minor changes. 
  • A day is measured from sunset to sunset, a week is seven days long, a month is either twenty-nine or thirty days long, and a year is made up of twelve lunar months plus about eleven days, or 353, 354, or 355 days. 
  • A thirteenth month of thirty days is intercalated in the third, sixth, eighth, eleventh, fourteenth, seventeenth, and nineteenth years of a nineteen-year cycle to reconcile the calendar with the yearly solar cycle; a leap year may have from 383 to 385 days. 
  • The civil calendar starts with Tishri, whose first day is Rosh Hashanah, the Jewish New Year. On Nisan 15, Passover, the religious calendar cycle starts (Pesach). 
  • The Babylonians provided the names for the months of the Jewish calendar. 

The months are generally referred to in numerical sequence in the preexilic books of the Bible, starting with Tishri, although there are four months recorded with other names: 

Nisan/Abib, Iyyar/Ziv, Tishri/Ethanim, and Heshvan/Bul: Nisan/Abib, Iyyar/Ziv, Tishri/Ethanim, and Heshvan/Bul: 

  1. Nisan is from the middle of March until the middle of April. 
  2. Iyyar: from the middle of April until the middle of May 
  3. Sivan is from the middle of May until the middle of June. 
  4. Tammuz is from the middle of June until the middle of July. 
  5. Av: mid-July to the middle of August 
  6. Elul is from the middle of August until the middle of September. 
  7. Tishri is from the middle of September until the middle of October. 
  8. Heshvan is from the middle of October until the middle of November. 
  9. Kislev is from the middle of November until the middle of December. 
  10. Tevet is from the middle of December until the middle of January. 
  11. Shevat is from the middle of January until the middle of February. 
  12. Adar: from the middle of February until the middle of March 

As required, the intercalary month of Adar II is added before Adar.

You may also want to learn more about Global Calendar Systems here.

Gregorian Calendar

Because the Julian year, averaging 365.25 days, was somewhat longer than the actual length of a solar year, which is known to be 365.242199 days, the discrepancy between the Julian calendar and the seasons had increased to 10 days by the late sixteenth century. 

  • Fixed holy days started to fall in the “wrong” season, both for the church and for farmers, who relied on specific holy days to schedule planting and harvesting. 
  • From the year 1582, Pope Gregory XIII issued a reform that removed 10 days; in that year, October 15 was the day following October 5. 
  • This adjustment, along with the removal of leap days in “century” years unless they were evenly divisible by 400 (e.g., 1600, 2000), rectified the calendar to the point that only rare “leap seconds” are required to keep months and seasons in sync today. 

The Gregorian calendar (N.S., or New Style), which was originally used exclusively in Roman Catholic nations, gradually gained acceptance across the West and is now used by the majority of the globe, at least for business and government.

You may also want to learn more about Global Calendar Systems here.

Julian Calendar

In 46 B.C., Julius Caesar ordered the conversion of the reformed Roman lunar calendar to a solar calendar. The ninety-day intercalation fixed a developing mismatch between the seasons and the months in which they had historically fallen. 

  • The Roman municipal year had become approximately three months “ahead” of the seasons prior to this intercalation, thus spring started in June. 
  • To make the correction, the year 46 B.C. was given 445 days and was dubbed ultimus annus confusionis, or "the final year of the confused counting." 
  • The new calendar, which was based on the Egyptian solar calendar, had a 365-day year with an extra day in February every fourth year. 
  • The Julian year has an average length of 365.25 days after adding this leap year and day, which is quite near to the real solar cycle. 

The Julian calendar (O.S., or Old Style) has been in use in the West for over 1,600 years, and it is still the foundation for the “Old Calendarist” Orthodox Christian liturgical calendar, which is utilized by all Orthodox Christian churches to establish Easter dates.

You may also want to learn more about Global Calendar Systems here.

Worldwide Calendar Systems

Julian, Gregorian, Jewish, Islamic, Hindu, Buddhist, Chinese, Mayan and Aztec, Baha'i, and Zoroastrian calendar systems are all used throughout the world. 

A calendar is a tool for keeping track of time using divisions such as days, weeks, months, and years. 

  • Some of these categories, such as months, are derived from observations of natural occurrences. 
  • Others, like as weeks, are completely random. 
  • People used to count by moon cycles (months), but when a more practical, shorter period was required, days were grouped, for example, the intervals between market days likely led to the adoption of the seven-day week. 

Beginning in the third century B.C., the traditionally Jewish seven-day week became a norm across Western culture. 


  • Despite the fact that the amount of daylight varies throughout the year, the day is a pretty natural divide. 
  • The Babylonians divided the day into twenty-four hours, although the hours fluctuated in length over the year. 
  • The day was first given scientific regularity with the invention of precise clocks, which was a consequence of the Renaissance's concern in nautical navigation. 


  • A lunar month, or the length of a complete cycle of the moon's phases, lasts approximately 29.5 days, is easily recognized by all, is short enough to be counted without large numbers.
  • A lunar month closely corresponds to the female menstrual cycle and, given its relationship to the tidal cycle, the duration of cyclic behavior in some marine animals. 

  • Its importance stemmed from its simplicity and ease of observation (assuming overcast skies are excluded), and it was extensively adopted as the foundation for calendars in many civilizations. 
  • The duration of each month varied depending on the culture; for example, the Babylonians alternated between twenty-nine and thirty-day months, while the Egyptians kept them at thirty days. 


  • The issue with using a lunar calendar is that the seasons are determined by the sun's cycles, not the moon's, and the predictability of the seasons is critical to agricultural productivity. 
  • Solar observation, either by monitoring the cycle of the midday shadow produced by a stick put vertically in the ground, or by complex astronomical calculations, may be used to predict the seasons. 
  • Both systems produced a solar year of around 365 days, which was incompatible with the twelve 29.5-day lunar months, which produced a 354-day year. In various ways, civilizations tried to harmonize lunar months with the solar year. 

The most important ancient effort was that of Egyptian astronomers, who set up the Roman calendar that Julius Caesar adopted, based on accurate mathematical measurements and drawing from Babylonian astronomy.

You may also want to learn more about Global Calendar Systems here.