how to pick difference between two datetime variables

[thanikondharish]

data ex ;
input dob:datetime15. start:datetime15. ;
format dob start  datetime15. ;
cards ;
9oct2019:12:50:00 9oct2019:13:55:00

9oct2019:12:50:00 10oct2019:13:55:00
;

how to do difference between two datetime vaiables 

ex:   1)01:05(one hour and five minutes)

[PaigeMiller]

data ex ;
input dob:datetime15. start:datetime15. ;
diff=start-dob;
format dob start  datetime15. diff time.;
cards ;
9oct2019:12:50:00 9oct2019:13:55:00
9oct2019:12:50:00 10oct2019:13:55:00
;

The difference is a straight subtraction, then you want the difference to be formatted into some format you happen to like.