hijri (islamic) calendar problem!

Question

I would convert Gregorian date to Hijri (Islamic) date. After may search on the web, I found a source code to convert it. I converted the code from Java and PHP to C base.

The implement some times working without any problem. But some days has problem.

I need your help either fix the implement or a available code that will work without any problem! BTW I found another source code (http://emr.cs.iit.edu/~reingold/calendar.C) that is C++ base. As I don't know C++ if anyone can convert that to C Base or Objective C would be prefect (still not sure this code will work correctly or not).

P.S. You can check the correct date in: islamicfinder.org/Hcal/index.php

void gregorian_to_hijri(int* h_y, int* h_m, int* h_d, int  g_y, int  g_m, int  g_d)
{
    int year, month, day;

    int zyr;
    int zd;
    int zm;
    int zy;

    float zjd;
    int zl;
    int zn;
    int zj;

    year = g_y;
    month = g_m;
    day = g_d;


    zyr = year;
    zd = day;
    zm = month;
    zy = zyr;

    if((zy > 1582) || ((zy == 1582) && (zm > 10)) || ((zy == 1582) && (zm == 10) && (zd > 14)))
    {
        zjd = ((1461 * (zy + 4800 + ((zm - 14) / 12))) / 4)
            + ((367 * (zm - 2 - 12 * (((zm - 14) / 12)))) / 12)
            - ((3 * (((zy + 4900 + ((zm - 14) / 12)) / 100))) / 4) + zd - 32075;
    }
    else
    {
        zjd = 367 * zy - ((7 * (zy + 5001 + ((zm - 9) / 7))) / 4)
            + ((275 * zm) / 9) + zd + 1729777;
    }

    zl = zjd - 1948440 + 10632;
    zn = ((zl - 1) / 10631);
    zl = zl - 10631 * zn + 354;
    zj = (((10985 - zl) / 5316)) * ((int)((50 * zl) / 17719))
        + ((zl / 5670)) * ((int)((43 * zl) / 15238));

    zl = zl - (((30 - zj) / 15)) * (((17719 * zj) / 50))
        - ((zj / 16)) * (((15238 * zj) / 43)) + 29;

    zm = ((24 * zl) / 709);
    zd = zl - ((709 * zm) / 24);
    zy = 30 * zn + zj - 30;

    *h_y = zy;
    *h_m = zm;
    *h_d = zd;
}

Please describe exactly what the problem is. Describe your input to the program. What are you expecting to get, and what are you getting? Also, please reformat your code. Read the http://stackoverflow.com/faq for details. — mpenkov, Dec 04 '10 at 15:49
"I need your help either fix the implement or" - we are not your workforce — fazo, Dec 04 '10 at 15:56
"But some days has problem." Telling us which days those are would be a big help. But you chose not to. :( — abelenky, Dec 04 '10 at 16:06
if you want to test your calendar visit: http://www.date2date.ir/ — PersianGulf, Jan 10 '15 at 01:13

Firoze Lafeer · Accepted Answer · 2010-12-05T06:38:34.393

10

Assuming this is for a Mac (Cocoa) or iOS (Cocoa Touch) app, since that's where you see Objective C most often, then you can just do something like this:

// Create a Gregorian Calendar
NSCalendar *gregorianCalendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];

// Set up components of a Gregorian date
NSDateComponents *gregorianComponents = [[NSDateComponents alloc] init];

gregorianComponents.day = 4;
gregorianComponents.month = 12;
gregorianComponents.year = 2010;

// Create the date
NSDate *date = [gregorianCalendar dateFromComponents:gregorianComponents];

[gregorianComponents release];
[gregorianCalendar release];


// Then create an Islamic calendar
NSCalendar *hijriCalendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSIslamicCivilCalendar];

// And grab those date components for the same date
NSDateComponents *hijriComponents = [hijriCalendar components:(NSDayCalendarUnit | 
                                                               NSMonthCalendarUnit |
                                                               NSYearCalendarUnit)
                                                     fromDate:date];


NSLog(@"[In Hijri calendar ->] Day: %ld, Month: %ld, Year:%ld", 
          [hijriComponents day],
          [hijriComponents month],
          [hijriComponents year]);

[hijriCalendar release];

If all you want is the current date, then you can skip setting up the gregorian date altogether and just do this:

// Create an Islamic calendar
NSCalendar *hijriCalendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSIslamicCalendar];

// And grab the date components for the current date
NSDateComponents *hijriComponents = [hijriCalendar components:(NSDayCalendarUnit | 
                                                               NSMonthCalendarUnit |
                                                               NSYearCalendarUnit)
                                                     fromDate:[NSDate date]];

[hijriCalendar release];

edited Dec 05 '10 at 06:38

answered Dec 04 '10 at 16:55

Firoze Lafeer

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Dear Firoze Laffer. Thanks. Fantastic example! you really did big favor. again thanks for your help! – Alish Dec 05 '10 at 06:06
2

Just one problem with it! I'm sure NSIslamicCalendar have a problem! if you test 7/12/2010 with NSIslamicCivilCalendar == 30/12/1431 and if you test the date with NSIslamicCalendar == 2/1/1432. However the correct date is: 1/1/1432!... Still have same problem with my code! – Alish Dec 05 '10 at 06:10
Hmm, that is interesting that it is one day off. Maybe post a bug report with Apple. As a temporary workaround, you could of course just add one day to the gregorian date before converting. – Firoze Lafeer Dec 05 '10 at 06:38
That was only example! You can find many problem in this year! I think in 1432 70% of result are wrong! – Alish Dec 05 '10 at 06:46
Can you list other examples? Perhaps there is a pattern. Also, is the other code you found consistent? Do they all produce the same dates? (other than Apple's) – Firoze Lafeer Dec 05 '10 at 06:54
yes I will. Unfortunately Apple is not the only one! All the codes I check have this problem. And interesting part is no one solve the issue! and apparently no one cares! But site such as http://www.islamicfinder.org/Hcal/index.php doesn't have any problem! – Alish Dec 05 '10 at 07:07
1

2011/3/5 == 1432/3/30 however with NSIslamicCalendar: 1443/3/30 2011/3/6 == 1432/4/1 however with NSIslamicCalendar: 1443/4/2 2011/4/4 == 1432/4/30 however with NSIslamicCalendar: 1443/5/1 2011/4/5 == 1432/5/1 however with NSIslamicCalendar: 1443/5/2 Also in middle of all the all dates with be mixed up! Also you can check more date with small implement. Many more you can find. – Alish Dec 05 '10 at 09:17

score 1 · Answer 2 · edited May 23 '17 at 11:44

1

Have a look at this topic: how to convert hijari date into gregorian date in java script?

The question mentions JavaScript but the top answer seems to have links to implementations in a variety of languages.

edited May 23 '17 at 11:44

Community

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answered Dec 04 '10 at 15:47

mpenkov

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score 1 · Answer 3 · answered Dec 04 '10 at 16:00

1

You should be able to do this in Objective-C (if that really is an option) using NSCalendar.

answered Dec 04 '10 at 16:00

Wevah

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Assuming this is for an iOS or Mac app. The OP doesnt say. – Firoze Lafeer Dec 04 '10 at 16:26
@Firoze Lafee: Quite true. (+1 on your answer, too!) – Wevah Dec 04 '10 at 17:25

hijri (islamic) calendar problem!

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