FUNCTION: DATETIMESEC_DOY DESCRIPTION: function to return seconds since 1/1/1970 00:00 UT, from date and time given as day, month, year, hour, minute, second, millisecond. USAGE (SAMPLE CODE FRAGMENT): ; set up a date and time (21 Mar '91, 00:01:01.000) doy = 80 year = 91 hour = 0 min = 1 sec = 1 msc = 0 ; convert to seconds sec_date_time = datetimesec_doy(year, doy, hour, min, sec, msc) ; print it out PRINT, sec_date_time --- Sample output would be 669517261 NOTES: If any of the fields are are out of range, the value will be carried. e.g. given date and time of 31/12/90, 25:01:00.1001, this will be converted to 1/1/91, 01:01:01: 001 If any of the input values are negitive, this is an error and -1 will This function can return seconds of days, or seconds since 1970 only by calling it with dates or times set to zero. If input values are arrays, then an array of N_ELEMENTS(inputs vals) of date strings and remainders will be returned. The number of array elements for all input parameters must be the same REVISION HISTORY: