I found some major bugs in my and also in 200_success's code. Since bug-determining and killing also a part of code-review I want to post this as an answer not as a comment. I think it's OK? right?
Input Correct output My output 200_success's output
12:01 am 12:59 pm 00:59 pm x 11:59 pm x
11:32 am 12:28 pm 00:28 pm x 12:28 pm
12:34 am 11:26 pm -1:26 pm x 11:26 pm
06:01 am 06:59 pm 06:59 pm 05:59 pm x
11:02 am 01:58 pm 01:58 pm 12:58 pm x
12:59 am 12:01 pm -1:1 pm x 11:01 pm x
x is marked as wrong output.