1IDATE(1) User Commands IDATE(1)
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6 ical - A Hijri/Islamic calendar (and converter)
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9 ical [--gregorian yyyymmdd] [--hijri yyyymmdd] [--umm_alqura]
10 [--fixed_view] [--dual] [--help]
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13 The ical program is a Hijri/Islamic calendar displayer. It utilizes
14 and includes a Gregorian to Hijri (and vice-versa) date converter. The
15 application uses and offers multiple calculation methods with not all
16 of them agreeing at all times. The reason for this multiplicity is due
17 to not having one agreed upon method and so various entities develop
18 and advocate their calculations.
19 ical is able to comprehend and calculate both pre-epoch or pre-Hijrah,
21 denoted as "B.H", as well as post-epoch or post-Hijrah, denoted as
22 "A.H", dates. ical also utilizes Gregorian's pre-epoch "B.C" and post-
23 epoch "A.D" dates and notes them per its output. When entering pre-
24 epoch years, negative numbers ought to be utilized.
25 ical when run without any command-line options uses the host machine's
27 Gregorian date and converts it to Hijri to display that month's view.
28 Entries enclosed by [] denote exact day specified.
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31 ical follows the usual GNU command line syntax, with long options
32 starting with two dashes (`-'). A summary of all options is noted
33 below:
34 -h, --help
36 Show summary of options
37 -g, --gregorian yyyymmdd
39 Specify the Gregorian date to be converted where 'y' stands for
40 year, 'm' for month and 'd' for day
41 -hi, --hijri yyyymmdd
43 Specify the Hijri date to be converted where 'y' stands for
44 year, 'm' for month and 'd' for day
45 -u, --umm_alqura
47 Specify to use the Umm Al-Qura calculation method (used mostly
48 in Saudi Arabia)
49 -f, --fixed_view
51 Show a fixed week view (ie. start on Sun and end on Sat) else
52 default to showing the preferred week view of the resulting cal‐
53 endar (Gregorian starts on Sunday, Hijri starts on Saturday)
54 -d, --dual
56 Show both converstion from and to calendar months simultaneously
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59 The Hijri calendar is used in most of the Arab world and is the sym‐
60 bolic calendar of the Islamic faithed worldwide. This calendar is
61 known as the "Hijri" (based on the word "Hijrah" - denoting migration
62 in Arabic) to signal Prophet Mohammed's (PBUH) migration from Makkah to
63 Medinah on Thursday, July 15, 622 AD (Julian).
64 The Islamic Hijri calendar is strictly lunar (ie. moon-based) with
66 twelve lunar months which do not correspond or track their solar coun‐
67 terparts (the Gregorian calendar is a solar or sun-based calendar).
68 Lunar years and thus Hijri years are, on average, about 354 days long
69 resulting in a Hijri year being roughly about 11 days shorter than its
70 Gregorian counterpart.
71 There is much discussion and confusion regarding how best to track the
73 Hijri calendar. A great deal of that confusion is based on the fact
74 that many relay on a human moon sighting to denote the start (or end)
75 of a month (each month of the Hijri calendar starts when a new moon's
76 crescent is observed or is made visible at sunset) as opposed to using
77 an empirical mathematic certainty. The methods presented in this
78 application and its underlying ITL library are strictly arithmetic in
79 nature and do NOT take moon-phases into consideration (in short, obser‐
80 vational approximation is not used).
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83 There is currently no Umm Al-Qura support.
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86 Report bugs on the web using http://bugs.arabeyes.org
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89 Written by Nadim Shaikli as part of the Arabeyes.org project.
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92 ical is subject to the GNU General Public License (GPL).
93 Copyright © 2005, Arabeyes, Nadim Shaikli.
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96 The ITL (Islamic Tools Library). It is the underlying requirement for
97 ical to function. The ITL library was created and is hosted at
98 www.arabeyes.org.
99ical January 05, 2005 IDATE(1)