2. Calendars


A calendar is a system for reckoning the passing of time. The principal problem in drawing up calendars arises from the fact that the solar day, the lunar month and the tropical year - the most immediate natural time units- are not simple multiples of each other. In practice a solution is found in basing the system either on the phases of the Moon (lunar calendar) or on changing of the seasons (solar calendar). The difficulty that days eventually get out of step with the Moon or the seasons is got over by adding in (intercalating) one or more extra days or months at regular intervals in an extended cycle of months or years.


The earliest Egyptian calendar had a year of 12 months with 30 days each, though later 5 extra days were added at the end of each year so that it approximated the tropical year of 365.25 days. In classical times, the Greeks came to use a lunar calendar in which 3 extra months were intercalated every eight years (the octannial cycle). Through about 432BC the astronomer Meton discovered that 235 lunar months fitted exactly into 19 years (Metonic cycle), this becoming the basis of the modern Jewish and ecclesiastical calendars.


The Roman calendar was reformed under Julius Caesar in 46BC fixing the year at 365 days but intercalating an additional day every fourth year (this giving an average 365.25 day-year). The Christians, who called it Anno Domini, adopted this Julian calendar and it continued in use until 16th century when it had become about 10days out of step with the seasons, the tropical year in fact being less than 365.25 day-years.


In 1582 AD Pope Gregory 13 ordered to omit 10 days from that year and not to give a leap year for century years unless divisible by 400 so that there would be no recurrence of any discrepancy in future. But since the error of one day occurs in

about 127 years, this adjustment will not make it fully error-free. This calendar was called the Gregorian calendar.


This Gregorian calendar was only slowly adopted particularly in non- catholic countries, the reform waiting until 1752 AD in England and its American colonies by which time 11 days had to be dropped. But in spite of all these defects it is still in civil use throughout the world even today. Various proposals for further reforms of this calendar have come to nothing.


The Hijra Calendar


At the time of the advent of the last Prophet of God Muhammad Musthafa (pbuh) the Jews were using the artificial lunar calendar. The Arabs too used it. The Prophet was born on the 12th of Rabiul Awwal according to the Jewish calendar. The Prophet did not approve this artificial lunar calendar for the Muslims. Muslims observed the lunar calandar based on the appearing of the crescent. In his last days the Prophet gave orders to revive the ancient natural lunar calendar fixing the months at 29 or 30 according to the appearing of the crescent, the dates tallying with the phases of the Moon as commanded in the Qur'aan. He banned the use of leap years and ordered to fix the months according to the appearing of the crescent so that the calendar would be totally natural, scientific and free of error. In this system the dates can be calculated up to infinity forewards or backwards. The common people can check the dates with the phases of the Moon. It does not require any formula. It is a perpetual calendar for mankind.


Calculation of the Hijra calendar


It is very easy to make the Hijra calendar. The data of the phases of the moon is easily available and this is the only requirement to draw the calendar. The expert astronomers prepare data of the phases of the moon. The laymen could check the data with the naked eyes by observing the phases of the moon.


The phases of the moon from BC 5000 to AD 5000 are available from U. S. Naval Observatory. The data for a century is published in the Ephemeris also. The newmoon date is the last date of the Islamic month. The months have 29 or 30 days according to the phases (Manzils) of the moon. An example is given below.


1990 Phases of the Moon

Universal Time

       d  h  m          d  h  m          d  h  m          d  h  m
                 JAN.   4 10 40   JAN.  11 04 57   JAN.  18 21 17
JAN.  26 19 20   FEB.   2 18 32   FEB.   9 19 16   FEB.  17 18 48
FEB.  25 08 54   MAR.   4 02 05   MAR.  11 10 58   MAR.  19 14 30
MAR.  26 19 48   APR.   2 10 24   APR.  10 03 18   APR.  18 07 02
APR.  25 04 27   MAY    1 20 18   MAY    9 19 31   MAY   17 19 45
MAY   24 11 47   MAY   31 08 11   JUNE   8 11 01   JUNE  16 04 48
JUNE  22 18 55   JUNE  29 22 07   JULY   8 01 23   JULY  15 11 04
JULY  22 02 54   JULY  29 14 01   AUG.   6 14 19   AUG.  13 15 54
AUG.  20 12 39   AUG.  28 07 34   SEPT.  5 01 46   SEPT. 11 20 53
SEPT. 19 00 46   SEPT. 27 02 06   OCT.   4 12 02   OCT.  11 03 31
OCT.  18 15 37   OCT.  26 20 26   NOV.   2 21 48   NOV.   9 13 02
NOV.  17 09 05   NOV.  25 13 11   DEC.   2 07 50   DEC.   9 02 04
DEC.  17 04 22   DEC.  25 03 16   DEC.  31 18 35

Hijra Calendar for the Year 1410- 1411AH (From Rajab to Jumadil Akhir)

Rajab first on 27-01-1990

Shaban first on 26-02-1990

Ramdan first on 27-03-1990

Shavval first on 26-04-1990

Zul Quaida first on 25-05-1990

Zul Hajj first on 23-06-1990

Muharrsam first on 23-07-1990

Safar first on 21-08-1990

Rabiul Avval first on 20-09-1990

Rabiul Akhir first on 19-10-1990

Jumadil Avval first on 18-11- 19990

Jumadil Akhir first on 18-12-1990