"%H:%M:%S", // could be the same or 24 hour one so try it too
"%I:%M %p", // 12hour with AM/PM but without seconds
"%H:%M", // and a possibly 24 hour version without seconds
+ "%I %p", // just hour with AM/AM
+ "%H", // just hour in 24 hour version
"%X", // possibly something from above or maybe something
// completely different -- try it last