If you calculate the time difference as a measure of seconds (diff = time2 - time1) and the difference is less than 24h, then the TIME. format works, it's just used in a different way than intended.

Time is expressed as a number in seconds, find below a sample program that shows differrent ways to display hour minutes and seconds. Please note that the TIME. format does print leading zero as blank, whereas TOD. prints leadings zeros. The user defined format MYTIME. combines the two to get all leading zeros (the MYTIME. uses "nested" formats)

proc format;
  value myTime
    0 - 36000 = [tod15.]
    36000 - high = [time15.]
  ;
run;

data test;
  do time = 0 to 20*24*3600 by 2750;
    time2 = time;
    time3 = time;
    output;
  end;
  format
    time time12.
    time2 tod15.
    time3 mytime.
  ;
run;