title: AngularJs: How to make stopwatch in time format
body: <p>I have number in $scope.number variable that is updating each second:<br>
  1 <br>
  2 <br>
  3 <br>
  70....<br></p>
  
  <p>how to get stopwatch with time format:<br>
  00:01<br>
  00:02<br>
  00:03<br>
  01:10</p>