question: public static String elapsedTimeDisplay ( Date dateStart , Date dateEnd ) { long diff = dateEnd . getTime ( ) - dateStart . getTime ( ) ; long diffMinutes = diff / ( 60 * 1000 ) % 60 ; long diffHours = diff / ( 60 * 60 * 1000 ) ; String mins = Long . toString ( diffMinutes ) ; if ( mins . length ( ) == 1 ) { mins = "0" + mins ; } return Long . toString ( diffHours ) + ":" + mins ; }
target:  elapsedTimeDisplay Get the elapsed time between two dates in readable format