scope.js

 restrict: 'EA',
      replace: false,
      scope: {
        interval: '=interval',
        startTimeAttr: '=startTime',
        endTimeAttr: '=endTime',
        countdownattr: '=countdown',
        finishCallback: '&finishCallback',
        autoStart: '&autoStart',
        language: '@?',
        fallback: '@?',
        maxTimeUnit: '=',
        seconds: '=?',
        minutes: '=?',
        hours: '=?',
        days: '=?',
        months: '=?',
        years: '=?',
        secondsS: '=?',
        minutesS: '=?',
        hoursS: '=?',
        daysS: '=?',
        monthsS: '=?',
        yearsS: '=?'
      },