question: public static String formatElapsedTime ( long time ) { if ( time < 0 ) { return "-" ; } long hours = 0 ; long minutes = 0 ; long seconds = 0 ; long elapsedSeconds = ( long ) ( time * UnitConversions . MS_TO_S ) ; if ( elapsedSeconds >= 3600 ) { hours = elapsedSeconds / 3600 ; elapsedSeconds -= hours * 3600 ; } if ( elapsedSeconds >= 60 ) { minutes = elapsedSeconds / 60 ; elapsedSeconds -= minutes * 60 ; } seconds = elapsedSeconds ; if ( hours > 0 ) { return String . format ( Locale . US , "%d:%02d:%02d" , hours , minutes , seconds ) ; } else { return String . format ( Locale . US , "%02d:%02d" , minutes , seconds ) ; } }
target:  Formats the elapsed timed in the form "MM:SS" or "H:MM:SS".