Is there any library or algorithm for Persian (Shamsi or Jalali) calendar in Android? [closed]

Answer 1

this method is very exact and simply also support leap years

Explain:

step 1: time today is contain current time

step 2: create two array for gregorian and jalali day in months(g_days_in_month&j_days_in_month)

step 3: create variable for retention difference time between calendars (gy,gm,gd) and variable g_day_no for days of years.

step 4: insert day of month and collect with days.

step 5: convert days of years to jalili years (jy)

at the end : set jalali month from day number, set jalali day from jalali day of month array.

good luck.

    Time today = new Time(Time.getCurrentTimezone());
    today.setToNow();
    int Day = (today.monthDay);             // Day of the month (0-31)
    int Month = (today.month);              // Month (0-11)
    int Year = (today.year);                // Year

    String persianDate = GregorianToJalali(Year, Month+1, Day);

  private String GregorianToJalali(int g_y, int g_m, int g_d)
{

  int[] g_days_in_month = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
  int[] j_days_in_month = {31, 31, 31, 31, 31, 31, 30, 30, 30, 30, 30, 29};

    int gy = g_y-1600;
    int gm = g_m-1;
    int gd = g_d-1;

        int g_day_no = 365*gy+div(gy+3,4)-div(gy+99,100)+div(gy+399,400);

        for (int i=0; i < gm; ++i)
          g_day_no += g_days_in_month[i];
        if (gm>1 && ((gy%4==0 && gy%100!=0) || (gy%400==0)))
         // leap and after Feb 
          g_day_no++;
        g_day_no += gd;

       int j_day_no = g_day_no-79;

        int j_np = div(j_day_no, 12053); //12053 = 365*33 + 32/4 
        j_day_no = j_day_no % 12053;

        int jy = 979+33*j_np+4*div(j_day_no,1461); // 1461 = 365*4 + 4/4 

        j_day_no %= 1461;

        if (j_day_no >= 366) {
          jy += div(j_day_no-1, 365);
          j_day_no = (j_day_no-1)%365;
        }

        int j;
        for (j=0; j < 11 && j_day_no >= j_days_in_month[j]; ++j)
          j_day_no -= j_days_in_month[j];
       int jm = j+1;
       int jd = j_day_no+1;


        String Result= jy+"/"+jm+"/"+jd;

        return (Result);
     }  


  private int div(float a, float b)
  {  
      return (int)(a/b); 
  }