visad/src/main/java/ucar/nc2/iosp/gempak/GempakUtil.java
public static int[] TG_FTOI(int[] iftime, int start) {

        int[] intdtf = new int[3];
        // If there is no forecast information, the string is stored as
        // date and time.

        if (iftime[start] < 100000000) {
            intdtf[0] = iftime[start];
            intdtf[1] = iftime[start + 1];
            intdtf[2] = 0;

            //  Otherwise, decode date/time and forecast info from the
            //  two integers. 

        } else {

            //  The first word contains MMDDYYHHMM.  This must be turned
            //  into YYMMDD and HHMM.

            intdtf[0] = iftime[start] / 10000;
            intdtf[1] = iftime[start] - intdtf[0] * 10000;
            int mmdd = intdtf[0] / 100;
            int iyyy = intdtf[0] - mmdd * 100;
            intdtf[0] = iyyy * 10000 + mmdd;

            //  The forecast time remains the same.

            intdtf[2] = iftime[start + 1];
        }
        return intdtf;
    }
public static int[] TG_FTOI(int[] iftime, int start) {

        int[] intdtf = new int[3];
        // If there is no forecast information, the string is stored as
        // date and time.

        if (iftime[start] < 100000000) {
            intdtf[0] = iftime[start];
            intdtf[1] = iftime[start + 1];
            intdtf[2] = 0;

            //  Otherwise, decode date/time and forecast info from the
            //  two integers. 

        } else {

            //  The first word contains MMDDYYHHMM.  This must be turned
            //  into YYMMDD and HHMM.

            intdtf[0] = iftime[start] / 10000;
            intdtf[1] = iftime[start] - intdtf[0] * 10000;
            int mmdd = intdtf[0] / 100;
            int iyyy = intdtf[0] - mmdd * 100;
            intdtf[0] = iyyy * 10000 + mmdd;

            //  The forecast time remains the same.

            intdtf[2] = iftime[start + 1];
        }
        return intdtf;
    }
This subroutine converts the two integers stored in a grid file
into three integers containing the date, time and forecast time.
@param  iftime  input time array
@param  start offset into the array
@return  int[3] with date time and forecast time