Just trying to improve Armen’s answer. You can use the $interval service to setup a timer.
var module = angular.module('myApp', []);
module.controller('TimeCtrl', function($scope, $interval) {
var tick = function() {
$scope.clock = Date.now();
}
tick();
$interval(tick, 1000);
});
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.11/angular.min.js"></script>
<div ng-app="myApp">
<div ng-controller="TimeCtrl">
<p>{{ clock | date:'HH:mm:ss'}}</p>
</div>
</div>