Date substring from a string

Hi All, Thanks a ton for all your messages. I am able to get the start time & end time out of the strings. Now I need to subtract

total_time=end_time-start_time

. But seems both start_time & end_time are strings, and I am getting result as

11:31:12-11:01:45

i.e.end_time-start_time

Will the start time always be less than the end time? Or, do you also need to adjust for times wrapping around midnight?

Do you want the start and end times at all, or should getttimes() just return the difference in times?

Do you want the difference as a number of seconds? Or, do you want it in the form HH:MM:SS ?