NASA Ocean Color

ocssw V2022

 static int days[] = {-1, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
  
 int daysInYear(int year) {
     if ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0)
         return 366;
     else return 365;
 }
  
 int daysInMonth(int year, int month) {
     if ((month == 2) && (daysInYear(year) == 366)) return 29;
     else return days[month];
 }
  
 int getCalDay(int year, int jday, int *month, int *day) {
     int i, sub_days, mdays;
     sub_days = jday;
     for (i = 1; i < 13; i++) {
         mdays = daysInMonth(year, i);
         sub_days -= mdays;
         if (sub_days <= 0)
             break;
     }
     if (sub_days == 0) {
         *month = i;
         *day = daysInMonth(year, i);
     } else {
         *month = i;
         *day = daysInMonth(year, i) + sub_days;
     }
     return 0;
 }
  
 int getJulianDay(int year, int month, int day) {
     int i;
     int julday = 0;
  
     if (month < 1 || month > 12)
         return -1;
     if (day < 1 || day > daysInMonth(year, month))
         return -1;
     for (i = 1; i < month; i++)
         julday += daysInMonth(year, i);
     julday += day;
     return julday;
 }