Directive to do a time ago with angular. Add "moment" : "latest" to your bower.json file.

display.html

<p>{{poast.created | fromNow}}</p>

filter.js

angular.module('app').filter('fromNow', function() {
  return function(date) {
    var newDate = new Date(date*1000);
    return moment(newDate).fromNow();
  };
});