By default Freevo uses a 24 hour military format. This is great if your dad was in the military, but quite confusing for us civilian folks. As of version 1.3.2 this is defined in freevo_config.py with the TV_TIMEFORMAT variable. By default it is set to '%H:%M'. To change it to a 12 hour format change it to '%I:%M'.
You will want to check out Python's strftime documentation to format it exactly how you want it.