Do you want the elapsed time? You should always specify am or pm. In this case it doesn't make any difference: 5:17 to 1:20 =8 hours and 3 minutes.
Hallo Guest!
What is 5:17 - 1:20
time of day:
5h 17min - 1h 20min = 3h 57min
Difference quotient
5/17 - 1/20 = (20 *5 - 17) / (17 * 20) = 83 / 340 = 0,24417647059
Greeting asinus :- )
!
Asinus: In English-speaking countries we don't go BACKWARDS in time!!!.
5:17pm to 1:20am is 8 hours and 3 minutes, or
5:17am to 1:20pm is 8 hours and 3 minutes!.
THIS IS CALLED ELAPSED TIME!.
Guest you are more full of dung than a constipated hog!
Asiuns’ answer is fine. No one can tell from the question if it hours or minutes, or a ratio.
I speak English (sort of) and I would not use a minus sign to mean “to” or elapsed time for that type of question.
Maybe in Anol Retentive -constipated hog, English you use it. :/