idate(1) - f14

1IDATE(1)                         User Commands                        IDATE(1)
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NAME

6       idate - A Gregorian/Meladi to/from Hijri/Islamic date converter
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SYNOPSIS

9       idate    [--gregorian    yyyymmdd]    [--hijri   yyyymmdd]   [--simple]
10       [--umm_alqura] [--help]
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DESCRIPTION

13       The idate program is a Gregorian to Hijri (and  vice-versa)  date  con‐
14       verter.   The  application uses and offers multiple calculation methods
15       with not all of them agreeing at all times.  The reason for this multi‐
16       plicity  is  due  to  not  having one agreed upon method and so various
17       entities develop and advocate their calculations.
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19       idate is able to comprehend and calculate both pre-epoch or pre-Hijrah,
20       denoted  as  "B.H",  as  well  as post-epoch or post-Hijrah, denoted as
21       "A.H", dates.  idate also  utilizes  Gregorian's  pre-epoch  "B.C"  and
22       post-epoch  "A.D"  dates  and notes them per its output.  When entering
23       pre-epoch years, negative numbers ought to be utilized.
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25       idate when run without any command-line options uses the host machine's
26       current Gregorian date and converts it to Hijri.
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OPTIONS

29       idate  follows  the  usual  GNU  command line syntax, with long options
30       starting with two dashes (`-').  A summary  of  all  options  is  noted
31       below:
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33       -h, --help
34              Show summary of options
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36       -g, --gregorian yyyymmdd
37              Specify  the Gregorian date to be converted where 'y' stands for
38              year, 'm' for month and 'd' for day
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40       -hi, --hijri yyyymmdd
41              Specify the Hijri date to be  converted  where  'y'  stands  for
42              year, 'm' for month and 'd' for day
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44       -s, --simple
45              Specify a simplified output mode
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47       -u, --umm_alqura
48              Specify  to  use the Umm Al-Qura calculation method (used mostly
49              in Saudi Arabia)
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BACKGROUND

52       The Hijri calendar is used in most of the Arab world and  is  the  sym‐
53       bolic  calendar  of  the  Islamic  faithed worldwide.  This calendar is
54       known as the "Hijri" (based on the word "Hijrah" -  denoting  migration
55       in Arabic) to signal Prophet Mohammed's (PBUH) migration from Makkah to
56       Medinah on Thursday, July 15, 622 AD (Julian) or July 19, 622 AD  (Gre‐
57       gorian).
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59       The  Islamic  Hijri  calendar  is  strictly lunar (ie. moon-based) with
60       twelve lunar months which do not correspond or track their solar  coun‐
61       terparts  (the  Gregorian  calendar  is a solar or sun-based calendar).
62       Lunar years and thus Hijri years are, on average, about 354  days  long
63       resulting  in a Hijri year being roughly about 11 days shorter than its
64       Gregorian counterpart.
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66       There is much discussion and confusion regarding how best to track  the
67       Hijri  calendar.   A  great deal of that confusion is based on the fact
68       that many rely on a human moon sighting to denote the start (or end) of
69       a  month  (each  month  of  the Hijri calendar starts when a new moon's
70       crescent is observed or is made visible at sunset) as opposed to  using
71       an  empirical  mathematic  certainty.   The  methods  presented in this
72       application and its underlying ITL library are strictly  arithmetic  in
73       nature and do NOT take moon-phases into consideration (in short, obser‐
74       vational approximation is not used).
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LIMITATIONS

77       The Umm Al-Qura option doesn't function with pre-epoch settings.
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REPORTING BUGS

80       Report bugs on the web using http://bugs.arabeyes.org
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AUTHOR

83       Written by Nadim Shaikli as part of the Arabeyes.org project.
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COPYRIGHT

86       idate is subject to the GNU General Public License (GPL).
87       Copyright © 2005, Arabeyes, Nadim Shaikli.
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