Gregorian-Hijri Dates Converter Codes

import java.util.Calendar;

/**

 * Gregorian-Hijri Dates Converter

 *

 *

 * This Code is used to convert Gregorian dates to Hijri Dates

 *

 *

 */

 

public class DateHigri {

     

     

    static double gmod(double n,double  m) {

        return ((n % m) + m) % m;

    }

 

    static double[] kuwaiticalendar(boolean adjust) {

        Calendar today = Calendar.getInstance();

        int adj=0;

        if(adjust){

            adj=0;

        }else{

            adj=1;

        }

         

        if (adjust) {

            int adjustmili = 1000 * 60 * 60 * 24 * adj;

            long todaymili = today.getTimeInMillis() + adjustmili;

            today.setTimeInMillis(todaymili);

        }

        double day = today.get(Calendar.DAY_OF_MONTH);

        double  month = today.get(Calendar.MONTH);

        double  year = today.get(Calendar.YEAR);

         

        double  m = month + 1;

        double  y = year;

        if (m < 3) {

            y -= 1;

            m += 12;

        }

 

        double a = Math.floor(y / 100.);

        double b = 2 - a + Math.floor(a / 4.);

     

        if (y < 1583)

            b = 0;

        if (y == 1582) {

            if (m > 10)

                b = -10;

            if (m == 10) {

                b = 0;

                if (day > 4)

                    b = -10;

            }

        }

 

        double jd = Math.floor(365.25 * (y + 4716)) + Math.floor(30.6001 * (m + 1)) + day

                + b - 1524;

         

        b = 0;

        if (jd > 2299160) {

            a = Math.floor((jd - 1867216.25) / 36524.25);

            b = 1 + a - Math.floor(a / 4.);

        }

        double bb = jd + b + 1524;

        double cc = Math.floor((bb - 122.1) / 365.25);

        double dd = Math.floor(365.25 * cc);

        double ee = Math.floor((bb - dd) / 30.6001);

        day = (bb - dd) - Math.floor(30.6001 * ee);

        month = ee - 1;

        if (ee > 13) {

            cc += 1;

            month = ee - 13;

        }

        year = cc - 4716;

 

        double wd = gmod(jd + 1, 7) + 1;

 

        double iyear = 10631. / 30.;

        double epochastro = 1948084;

        double epochcivil = 1948085;

 

        double shift1 = 8.01 / 60.;

 

        double z = jd - epochastro;

        double cyc = Math.floor(z / 10631.);

        z = z - 10631 * cyc;

        double j = Math.floor((z - shift1) / iyear);

        double iy = 30 * cyc + j;

        z = z - Math.floor(j * iyear + shift1);

        double im = Math.floor((z + 28.5001) / 29.5);

        if (im == 13)

            im = 12;

        double id = z - Math.floor(29.5001 * im - 29);

 

        double[]  myRes = new double[8];

 

        myRes[0] = day; // calculated day (CE)

        myRes[1] = month - 1; // calculated month (CE)

        myRes[2] = year; // calculated year (CE)

        myRes[3] = jd - 1; // julian day number

        myRes[4] = wd - 1; // weekday number

        myRes[5] = id; // islamic date

        myRes[6] = im - 1; // islamic month

        myRes[7] = iy; // islamic year

 

        return myRes;

    }

    static String writeIslamicDate() {

        String[] wdNames = {"Ahad", "Ithnin", "Thulatha", "Arbaa", "Khams",

                "Jumuah", "Sabt"};

        String[] iMonthNames = {"Muharram", "Safar", "Rabi'ul Awwal",

                "Rabi'ul Akhir", "Jumadal Ula", "Jumadal Akhira", "Rajab",

                "Sha'ban", "Ramadan", "Shawwal", "Dhul Qa'ada", "Dhul Hijja"};

        // This Value is used to give the correct day +- 1 day

        boolean dayTest=true;

        double[] iDate = kuwaiticalendar(dayTest);

        String outputIslamicDate = wdNames[(int) iDate[4]] + ", " + iDate[5] + " "

                + iMonthNames[(int) iDate[6]] + " " + iDate[7] + " AH";

         

        return outputIslamicDate;

    }

}