function time_diff, time
;
;   Name: time_diff
;
;   Purpose: returns differential time in seconds between two times in
;      standard sxt internal format
;
;   History: slf, 5/91
;-
;
daysecs = 86400L
;
ms_diff   = time(1).(0) - time(0).(0)
;
days_diff = time(1).(1) - time(0).(1)
;
return, (days_diff * daysecs) + (ms_diff/1000)
end