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Islamic

As of Version 10.0, calendar functionality is built into the Wolfram Language »

Islamic

represents the Islamic calendar system.

Details and Options

  • To use Islamic, you first need to load the Calendar Package using Needs["Calendar`"].
  • Islamic is a value for the Calendar option, and can be used as an argument to CalendarChange.
  • This calendar began on {622,7,16} Julian, or {1,1,1} in the Islamic calendar (one date given for the Hegira).

Examples

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Basic Examples  (5)Summary of the most common use cases

In[1]:=1
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https://wolfram.com/xid/0j076gwu0niy-iuyy1z

The argument Islamic to CalendarChange converts between Western (Gregorian) dates and Islamic dates. This computes the Islamic date of January 1, 2000:

In[2]:=2
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https://wolfram.com/xid/0j076gwu0niy-ny1qmk
Out[2]=2
In[1]:=1
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https://wolfram.com/xid/0j076gwu0niy-9n50f

The Islamic calendar has the following months:

In[2]:=2
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https://wolfram.com/xid/0j076gwu0niy-0jhlr

The above date is therefore the 24th of Ramadan, 1420.

In[1]:=1
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https://wolfram.com/xid/0j076gwu0niy-i3etgm

The Western date for the beginning of Ramadan of the Islamic year 1420:

In[2]:=2
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https://wolfram.com/xid/0j076gwu0niy-w72mk
Out[2]=2
In[1]:=1
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https://wolfram.com/xid/0j076gwu0niy-dfha8m

The Islamic year has fewer days than the Western year:

In[2]:=2
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https://wolfram.com/xid/0j076gwu0niy-yvnce
Out[2]=2
In[3]:=3
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https://wolfram.com/xid/0j076gwu0niy-rwqce
Out[3]=3
In[1]:=1
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https://wolfram.com/xid/0j076gwu0niy-eobhkk

The Islamic calendar is purely lunar (time of month corresponds to phase of the moon) but does not keep track of seasons, since there is no leap month. The Islamic calendar moves backward with respect to the Western calendar; for example, the start of Ramadan in successive years:

In[2]:=2
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https://wolfram.com/xid/0j076gwu0niy-kgrkec
Out[2]=2
In[3]:=3
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https://wolfram.com/xid/0j076gwu0niy-di2rk4
Out[3]=3
In[4]:=4
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https://wolfram.com/xid/0j076gwu0niy-euxh6m
Out[4]=4

Applications  (1)Sample problems that can be solved with this function

In[1]:=1
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https://wolfram.com/xid/0j076gwu0niy-dcabxn

A program that computes the first and last dates of Ramadan for a given Western calendar year for the first Ramadan beginning that year:

In[2]:=2
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https://wolfram.com/xid/0j076gwu0niy-g21g5
In[3]:=3
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https://wolfram.com/xid/0j076gwu0niy-cwq7jx
Out[3]=3

Note that Ramadan can overlap January 1, as in 2000:

In[4]:=4
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https://wolfram.com/xid/0j076gwu0niy-biyd0b
Out[4]=4

There is also the possibility that two Ramadans begin in the same Western year, as in 1932. The program returns the first Ramadan beginning that year:

In[5]:=5
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https://wolfram.com/xid/0j076gwu0niy-orx3n
Out[5]=5
In[6]:=6
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https://wolfram.com/xid/0j076gwu0niy-b093ga
Out[6]=6

Ramadan of the following Islamic year also began in 1932:

In[7]:=7
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https://wolfram.com/xid/0j076gwu0niy-eytm99
Out[7]=7

Possible Issues  (1)Common pitfalls and unexpected behavior

In[1]:=1
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https://wolfram.com/xid/0j076gwu0niy-lbw0x

Since the names and the numerical order of the Islamic months are not well known in the Western world, it is useful to have the list of names:

In[2]:=2
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https://wolfram.com/xid/0j076gwu0niy-bxqu4p