Zoroastrian calendar


Adherents of Zoroastrianism use three distinct versions of traditional calendars for liturgical purposes. Those all derive from medieval Iranian calendars and ultimately are based on the Babylonian calendar as used in the Achaemenid Empire. Qadimi is a traditional reckoning introduced in 1006. Shahanshahi is a calendar reconstructed from the 10th century text Denkard. Fasli is a term for a 1906 adaptation of the 11th century Jalali calendar following a proposal by Kharshedji Rustomji Cama made in the 1860s.
A number of Calendar eras are in use:
  • A tradition of counting years from the birth of Zoroaster was reported from India in the 19th century. There was a dispute between factions variously preferring an era of 389 BCE, 538 BCE, or 637 BCE.
  • The "Yazdegerdi era" counts from the accession of the last Sassanid ruler, Yazdegerd III. This convention was proposed by Cama in the 1860s but has since also been used in conjunctions with Qadimi or Shahanshahi reckoning. An alternative "Magian era" was set at the date of Yazdegerd's death in 652.
  • "Z.E.R." or "Zarathushtrian Religious Era" is a convention introduced in 1990 by the Zarathushtrian Assembly of California set at the vernal equinox of 1738 BCE.

    History

Achaemenid period

Calendrical traditions in ancient Iran can be traced back to the 2nd millennium B.C. Yet the earliest fully preserved calendar actually dates only from the Achaemenid Empire period, starting in the sixth century BC.
The Old Persian calendar, similar to the Babylonian calendar, was lunisolar, with twelve months of thirty days each. The Old Persian inscriptions mention only eight month names, so the other four names have been reconstructed from the Elamite transcriptions.
The Achaemenids used the lunisolar calendar at least until 459 B.C., because this is the date of the last preserved document using such a calendar.
The Babylonian calendar, being lunisolar, used an intercalary month roughly once every third year.
It is not clear exactly when the Zoroastrian calendar was first introduced. Nevertheless, because of its similarities with the Egyptian calendrical system, it can be hypothesized that its introduction was in the 5th century BCE, in the period during which Egypt was ruled by the Achaemenids. According to S. Stern, this happened during the first century of Achaemenid rule over Egypt, or from 525 to 430 BCE.
Scholars distinguish between the Old Avestan and a Later Avestan calendars. However, given that both have been reconstructed on the basis of similar sources, there are some disputes in this area.
The earliest Zoroastrian calendar follows the Babylonian in relating the seventh and other days of the month to Ahura Mazda.
In the civil calendar, intercalations did not always follow a regular pattern, but during the reign of Artaxerxes II astronomers utilised a 19-year cycle which required the addition of a month called Addaru II in years 3, 6, 8, 11, 14 and 19, and the month Ululu II in year 17 of the cycle.
A 365-day calendar, with months largely identical to the Egyptian calendar, was introduced shortly after the conquest of Egypt by the Achaemenid ruler Cambyses.
Scholars are divided on whether this 365 day calendar was in fact preceded by a 360-day calendar of Zoroastrian observances.

Hellenistic period

Following Alexander's invasion of Persia in 330 BCE, the Seleucid instituted the Hellenic practice of counting years from the start of a fixed era, as opposed using regnal years.
The regnal era of Alexander is now referred to as the Seleucid era.
The Parthians, who succeeded the Seleucids, continued the Seleucid/Hellenic tradition.

Parthian to Sassanid period

In 224 CE, when the Babylonian calendar was replaced by the Zoroastrian, 1 Frawardin and the New Year celebration of Nawruz had drifted to 1 October. The older custom of counting regnal years from the monarch's coronation was reinstated. At this point the calendar was realigned with the seasons by delaying the epagomenal days by eight months and adjusting the dates of the gahanbars accordingly.
This caused confusion, since the new year now fell five days earlier than before, and some people continued to observe the old date. After 46 years, with 1 Frawardin now on 19 September, another calendar reform was implemented by Ardashir's grandson Hormazd I. During the first years after implementation of the new Gatha days, the population had not universally adopted the new dates for religious festivals, resulting in "official" celebrations takings place five days earlier than popular celebrations. In later years the population had observed the Gatha days, but the original five day discrepancy persisted. Hormazd's reform was to link the popular and official observance dates to form continual six-day feasts. Nawruz was an exception: the first and the sixth days of the month were celebrated as different occasions. Lesser Nawruz was observed on 1 Frawardin. 6 Frawardin became Greater Nawruz, a day of special festivity. Around the 10th century CE, the Greater Nawruz was associated with the return of the legendary king, Jamsed; in contemporary practice it is kept as the symbolic observance of Zoroaster's birthday, or Khordad Sal.
Mary Boyce has argued that sometime between 399 CE and 518 CE the six-day festivals were compressed to five days. The major feasts, or gahambars, of contemporary Zoroastrian practice, are still kept as five-day observances today.

Medieval period

The Bundahishn, a pseudo-Avestan treatise written in the early Islamic period
replaces the "Age of Alexander" with an "Ageo of Zoroaster", placed "258 years before Alexander" .
By the reign of Yazdegird III, the religious celebrations were again somewhat adrift with respect to their proper seasons. The calendar had continued to slip against the Julian calendar since the previous reform at the rate of one day every four years. Therefore, in 632, the new year was celebrated on 16 June. By the 9th century, the Zoroastrian theologian Zadspram had noted that the state of affairs was less than optimal, and estimated that at the time of Final Judgement the two systems would be out of sync by four years.

Calendar eras

Zoroastrian Yazdegerd Era starts on 16 June 632 CE. Yazdegird III was the last monarch of the Sasanian dynasty, and since the custom at that time was to count regnal years since the monarch ascended the throne, the reckoning of years was continued, in the absence of a Zoroastrian monarch, among some Zoroastrians.
Zoroastrian dates are distinguished by the suffix Y.Z. for "Yazdegirdi Era". The usage "AY" is also found.
Yet another form of reckoning is the Zarathushtrian Religious Era, adopted in 1990 CE by the Zarathushtrian Assembly of California. This is based on the putative association of the mission of Zoroaster with the dawn of the astrological Age of Aries, calculated for this purpose to have been the northern vernal equinox of 1738 BCE. Hence the year 3738 ZRE began in 2000 CE. The Zoroastrian community, both in Iran and in diaspora, have also been said to have accepted it, the former doing so in 1993 CE. A briefing paper from the Zoroastrian Trust Funds of Europe indicates that they recognise this usage to have been pragmatically adopted by Zoroastrians in Iran, while the diaspora continues to use the YZ system.

Qadimi calendar

The Qadimi or "ancient" calendar is the traditional calendar in use since 1006 CE.
In 1006 CE, the month Frawardin had returned to the correct position so that 1 Frawardin coincided with the northern vernal equinox. The religious festivals were therefore returned to their traditional months, with Nawruz once again being celebrated on 1 Frawardin.
The Julian Day Number corresponding to 16 June 632 CE is 1952063.
The Julian Day Number of Nowruz, the first day, of Year Y of the Yazdegirdi Era is therefore 1952063 + × 365.
22 July AD 2000 was Nowruz and the first day of 1370 Y.Z. according to the Qadimi reckoning.
In the Julian year 1300 CE, 669 Y.Z. began on 1 January, and 670 Y.Z. on 31 December of the same year.

Shahanshahi calendar

The Shahanshahi calendar or "imperial" calendar
is the system described in Denkard, a 9th-century Zoroastrian text.
It explicitly acknowledged several methods of intercalation:
  • a leap-day every 4 years;
  • adding ten days every 40 years;
  • a leap-month of 30 days once every 120 years;
  • 5 months once every 600 years;
1,461 Zoroastrian years equal 1,460 Julian years.
The Denkard then states:
The Denkard – which was not Zoroastrian scripture but a religious manual – therefore favoured the solution of a leap-month once every 120 years, with a fall-back of adding 5 months after 600 years if this were missed. This practice was not, however, adopted by Zoroastrians living in Islamic Persia.
The Parsis had knowledge of The Denkard's proposal: at some point between 1125 and 1129, the Parsi-Zoroastrians of the Indian subcontinent inserted such an embolismic month, named Aspandarmad vahizak. That month would also be the last month intercalated: subsequent generations of Parsis neglected to insert a thirteenth month.
Around 1720 CE, an Iranian Zoroastrian priest named Jamasp Peshotan Velati travelled from Iran to India. Upon his arrival, he discovered that there was a difference of a month between the Parsi calendar and his own calendar. Velati brought this discrepancy to the attention of the priests of Surat, but no consensus as to which calendar was correct was reached. Around 1740 CE, some influential priests argued that since their visitor had been from the ancient 'homeland', his version of the calendar must be correct, and their own must be wrong. On 6 June 1745 CE, a number of Parsis in and around Surat adopted the calendar which had continued in use in Iran, now to be identified as the Qadimi reckoning. Other Parsis continued to use the reckoning which had become traditional in India, and call their calendar Shahanshahi.
Arzan Lali the author of Zoroastrian Calendar Services website comments that "... adherents of other variants of the Zoroastrian calendar denigrate the Shenshai or Shahenshahi as 'royalist'."
21 August 2000 CE was Nawruz, and the first day of 1370 Y.Z. according to the Shahanshahi reckoning.
Because the one-off intercalation of 30 days happened sometime before the Nawruz of 1129 CE, we can be confident that in that Julian year, 498 YZ began on 12 February by the Qadimi reckoning, but 14 March by the recently introduced Shahanshahi.
The Julian Day Number of Nawruz, the first day, of all subsequent Shahanshahi years Y of the Yazdegirdi Era is therefore 1952093 + × 365.