cdm/src/main/java/ucar/nc2/iosp/sigmet/SigmetIOServiceProvider.java
static String calcTime(int t, int t0) {
    StringBuilder tim = new StringBuilder();
    int[] tt = new int[3];
    int mmh = (t + t0) / 60;
    tt[2] = (t + t0) % 60;                  // Define SEC
    tt[0] = mmh / 60;                     // Define HOUR
    tt[1] = mmh % 60;                     // Define MIN
    for (int i = 0; i < 3; i++) {
      String s = Integer.toString(tt[i]);
      int len = s.length();
      if (len < 2) {
        s = "0" + tt[i];
      }
      if (i != 2) s += ":";
      tim.append(s);
    }
    return tim.toString();
  }
static String calcTime(int t, int t0) {
    StringBuilder tim = new StringBuilder();
    int[] tt = new int[3];
    int mmh = (t + t0) / 60;
    tt[2] = (t + t0) % 60;                  // Define SEC
    tt[0] = mmh / 60;                     // Define HOUR
    tt[1] = mmh % 60;                     // Define MIN
    for (int i = 0; i < 3; i++) {
      String s = Integer.toString(tt[i]);
      int len = s.length();
      if (len < 2) {
        s = "0" + tt[i];
      }
      if (i != 2) s += ":";
      tim.append(s);
    }
    return tim.toString();
  }
Calculate time as hh:mm:ss

@param t  number of seconds since midnight for start of sweep
@param t0 time in seconds from start of sweep
@return time as string "hh:mm:ss"