the passage of time using the Islamic (Hijrah) calendar.
This calendar has twelve lunar months, the beginnings and endings of
which are determined by the sighting of the crescent moon.
Years are counted since the Hijrah, which is when the Prophet
Muhammad migrated from Mecca to Madinah (approximately July 622
calendar was first introduced by the close companion of the Prophet,
'Umar ibn Al-Khattab. During his leadership of the Muslim
community, in approximately 638 A.D., he consulted with his advisors
in order to come to a decision regarding the various dating systems
used at that time. It was agreed that the most appropriate
reference point for the Islamic calendar was the Hijrah,
since it was an important turning point for the Muslim community.
After the emigration to Madinah (formerly known as Yathrib), the
Muslims were able to organize and establish the first real Muslim
"community," with social, political, and economic
independence. Life in Madinah allowed the Muslim community to
mature and strengthen, and the people developed an entire society
based on Islamic principles.
calendar is the official calendar in many Muslim countries,
especially Saudi Arabia. Other Muslim countries use the Gregorian
calendar for civil purposes and only turn to the Islamic calendar
for religious purposes.
The Islamic Calendar, which is based purely on lunar cycles, was
first introduced in 638 C.E. by the close companion of the
Prophet and the second Caliph, `Umar ibn Al-KHaTTab
(592-644 C.E.) RAA. He did it in an attempt to rationalize the
various, at times conflicting, dating systems used during his
time. `Umar consulted with his advisors on the starting date of
the new Muslim chronology. It was finally agreed that the most
appropriate reference point for the Islamic calendar was the Hijrah.
The actual starting date for the Calendar was chosen (on the
basis of purely lunar years, counting backwards) to be the first
day of the first month (1 Muharram) of the year of the Hijrah.
The Islamic (Hijrah) calendar (with dates that fall within the
Muslim Era) is usually abbreviated A.H. in Western languages
from the latinized Anno Hegirae, "in the year of the
Hegira". Muharram 1, 1 A.H. corresponds to July 16, 622 C.E.
SPECIFICATION AND METHOD
The Islamic (Hijrah) year consists of twelve (purely lunar)
months. They are: (1) Muharram; (2) Safar; (3) Rabiulawall;
(4) Rabiulakhir; (5) Jamadilawal; (6) Jamadilakhir;
(7) Rejab; (8) Syaaban; (9) Ramadhaan; (10) Syawal; (11)
Zulkaedah; and (12) Zulhijjah.
The most important dates in the Islamic (Hijrah) year are: 1
Muharram (Islamic new year); 27 Rejab (Isra & Miraj); 1
RamaDHaan (first day of fasting); 17 Ramadhan (Nuzul Al-Qur'an);
Last 10 days of Ramadhaan which include Laylatu al-Qadar; 1
Syawal (AidilFitri); 8-10 Zulhijjah (the Hajj to Makkah);
and 10 Zulhijjah (Aidiladha). It is considered a divine command to use a
with 12 (purely) lunar months without intercalation.
Since the Islamic calendar is purely lunar, as opposed to solar
or luni-solar, the Muslim (Hijrah) year is shorter than the
Gregorian year by about 11 days, and months in the Islamic
(Hijrah) year are not related to seasons, which are fundamentally
determined by the solar cycle. This means that important Muslim
festivals, which always fall in the same Hijrah month, may occur
in different seasons. For example, the Hajj and Ramdhaan. It is only over
a 33 year cycle that lunar months take a complete turn and fall
during the same season.
For religious reasons, the beginning of a
Hijrah month is
marked not by the start of a new moon, but by a physical (i.e.,
an actual human) sighting of the crescent moon at a given
locale. From the Fiqhi standpoint, one may begin the fast in
Ramdhaan, for example, based on "local" sighting
(IKHTILAF AL-MATALE') or based on sighting anywhere in the
Muslim World. Although different, both of
these positions are valid Fiqhi positions.
Astronomically, some data are definitive and conclusive (i.e.
the time of the BIRTH of a new moon). However, determining the VISIBILITY
of the crescent is not as definitive or conclusive; rather it is
dependent upon several factors, mostly optical in nature. This
makes it difficult to produce (in advance) Islamic calendars
that are reliable (in the sense that they are consistent with
actual crescent visibility).
Efforts for obtaining an astronomical criterion for
predicting the time of first lunar visibility go back the the
Babylonian era, with significant improvements and work done
later by Muslim and other scientists. These efforts have
resulted in the development in a number of criteria for
predicting first possible sighting of a crescent. However, there
remains a measure of uncertainty associated with all criteria
developed thus far. Moreover, there has been little work in the
area of estimating crescent visibility on global (as opposed to
local) scale. Until this happens, no Hijrah calendar software can
be 100% reliable, and actual crescent sighting remains essential
especially for fixing important dates such as the beginning of
Ramadhaan and the two `iyds ("Hari Raya").
The slight differences in printed Islamic calendars,
worldwide, can therefore be traced to two primary factors: (1)
the absence of a global criterion for first visibility; and (2)
the use of different visibility criterion (or method of
calculation). Weather conditions and differences in the
observer's location also explain why there are sometimes
differences in the observances of Islamic dates, worldwide.
Readers interested in further information should consult
Mohammad Ilyas' excellent book ``A Modern Guide to Astronomical
Calculations of Islamic Calendar, Times & Qibla,'' Berita
Publishing, 1984, (ISBN: 967-969-009-1). The book contains a
thorough discussion of the Islamic calendrical system and
related historical and scientific developments. It also presents
an interesting proposal for a universal Islamic Calendar based
on a global visibility criterion and the concept of a Lunar Day
(or International Lunar Date Line).
Waleed A. Muhanna