Actually what I put in for the hour, mintue, seconds list you can pick 99:59:59. It is not dependent on the actual movie time. I suggest you some how feed over the movie current time so that if you only want to adjust one part of it, say minutes, you don't have to set the hours and seconds too.
currently when it starts time code is 0:0:0. You have to select the hours, minutes, seconds.
if you did not notice you must tap on time list to make change before hitting other button.