Iranian Calendars

Before attempting to review the major holidays and festivals celebrated in

Iran, it is necessary to explain some features of the various systems of dating

in use there. The Gregorian calendar familiar to Westerners and now used

in many countries around the world is known in Iran, but it has no offi –

cial standing (in fact, at times its use has even been outlawed). Dates from

that calendar may be given on newspapers or various documents, especially

those involving non-Iranians, but this is purely for ease of reference. Instead,

Iranians use two other calendar systems for offi cial purposes: the Islamic lunar

calendar ( qamari ) and the Iranian solar calendar ( shamsi ).

The lunar calendar was introduced in Iran following the Arab conquest

and the spread of Islam. For many centuries it was the only calendar in

general use, and it still serves as the only system for dating Islamic religious

holidays. It was based on an era ( hejri ) beginning with the year of the Prophet

Mohammad’s emigration from Mecca to Medina (the Hegira [ hejrat ] in a.d.

622). The year consists of 12 months, each of which begins with the sighting

of a new moon. The Arabic names of the months are used, but most are pronounced

somewhat differently in Persian: Moharram, Safar, Rabi‘-ol-Avval

(I), Rabi‘-ol-Âkher (II), Jomâdâ-ol-Ulâ (I), Jomâdâ-ol-Âkhereh (II), Rajab,

Sha‘ban, Ramazân, Shavvâl, Zu‘l-Qa‘deh, and Zu‘l-Hejjeh (in colloquial

Persian, the latter two are often pronounced as Zi-Qa‘deh and Zi‘l-Hejjeh

or Zi-Hajjeh). Since a lunar cycle takes just over 29.5 days, and the sighting

of a new moon depends greatly on local conditions, it is possible any given

month might have 29 or 30 days. As a matter of convenience, printed calendars

assume the months will alternate between 30 and 29 days, with the last

month having one or the other. This enables one to estimate fairly closely

when a holiday or other event should occur, but the dates may be off a bit

depending on the actual astronomical observations.

Long before the coming of Islam, Iranians used a very sophisticated solar

calendar, usually referred to in its classical form as the New Avestan Calendar,

that was closely tied to the beliefs and practices of the Zoroastrian religion.

The year began at the moment of the vernal (spring) equinox, and consisted

of 12 equal months of 30 days. There were no weeks, and each day had its

own name. Since the tropical year (the time to complete the cycle from one

spring equinox to the next) is actually 365.2422 days, intercalary days

were added as needed to make up the difference. Other adjustments were to

be made every 120 and 1,440 years in order to keep the calendar in sync with

the actual position of the sun.

A key difference between the two calendar systems is that dates in the solar

system correspond consistently to seasons, while those in the lunar calendar

do not. Since the lunar year (354.367 days) is shorter than the solar year,

dates gradually cycle backward through the seasons: For example 1 Moharram

1400 fell on November 21, 1979, but now, in 2006/1427, 1 Moharram has

moved all the way back to January 31. Even in the Islamic period, variations

of the old solar calendar thus continued to be used, especially for fi scal

and administrative purposes (since it worked better for assessments tied to

the agricultural season). The most technically advanced and widely accepted

of these solar calendars was the Jalâli calendar, devised by a committee of

celebrated mathematicians and astronomers in 1079.

In 1911, during the course of the Iranian Constitutional Revolution, the

Majles made a version of this solar calendar the offi cial one. It used the names

The result of all this is that certain holidays are determined on the basis

of the national or solar calendar, while Islamic religious holidays follow the

lunar calendar (somewhat like the way Independence Day is a fi xed date in

the civil calendar of the United States, but the dates of Easter or Yom Kippur

vary according to a different religious calendar). Converting the lunar dates

to the equivalent in other calendars also involves a certain amount of imprecision

and variation from year to year, but the Iranian solar dates can be given

an equivalent date in the Gregorian calendar quite easily. The only complication

is that the start of the year on the vernal equinox always corresponds to

1 Farvardin but in the Gregorian calendar may be March 21 or March 20

(in leap years). Thus the Gregorian equivalents given in the following discussion

would be advanced one day in leap years (e.g., Islamic Republic Day, 12

Farvardin, usually falls on April 1, the Gregorian date on which the event it

commemorates actually occurred, but in 2004, a leap year, it was celebrated

on March 31).