var app = angular.module('plunker', []);

app.controller('MainCtrl', function($scope) {
  $scope.va1 = '123';
});


app.directive('datetimez', function() {
    return {
        restrict: 'A',
        require : 'ngModel',
        link: function(scope, element, attrs, ngModelCtrl) {
          element.datetimepicker({
            dateFormat:'dd/MM/yyyy hh:mm:ss',
            language: 'pt-BR'
          }).on('changeDate', function(e) {
            ngModelCtrl.$setViewValue(e.date);
            scope.$apply();
          });
        }
    };
});
<!DOCTYPE html>
<html ng-app="plunker">

  <head>
    <meta charset="utf-8" />
    <title>AngularJS Plunker</title>
    <script>document.write('<base href="' + document.location + '" />');</script>
    <link rel="stylesheet" href="style.css" />
    <link href="http://netdna.bootstrapcdn.com/twitter-bootstrap/2.2.2/css/bootstrap-combined.min.css" rel="stylesheet">
    <link rel="stylesheet" type="text/css" media="screen" href="http://tarruda.github.com/bootstrap-datetimepicker/assets/css/bootstrap-datetimepicker.min.css">
    
    <script type="text/javascript" src="http://cdnjs.cloudflare.com/ajax/libs/jquery/1.8.3/jquery.min.js">
    </script>
    <script type="text/javascript" src="http://netdna.bootstrapcdn.com/twitter-bootstrap/2.2.2/js/bootstrap.min.js">
    </script>
    <script type="text/javascript" src="http://tarruda.github.com/bootstrap-datetimepicker/assets/js/bootstrap-datetimepicker.min.js">
    </script>
    <script type="text/javascript" src="http://tarruda.github.com/bootstrap-datetimepicker/assets/js/bootstrap-datetimepicker.pt-BR.js">
    </script>
    <script data-require="angular.js@1.0.x" src="https://ajax.googleapis.com/ajax/libs/angularjs/1.0.8/angular.min.js" data-semver="1.0.8"></script>
    
    
    <script src="app.js"></script>
  </head>

  <body>
    <div class="container container-fluid" ng-controller="MainCtrl">
      2+2={{2+2}}, var1={{var1}}
      <form class="form-horizontal" novalidate name="form" ng-submit="submit()">
      <div class="well">
        <div id="date" class="input-append" datetimez ng-model="var1">
          <input data-format="MM/dd/yyyy HH:mm:ss PP" type="text" id="input1" name="input1"></input>
          <span class="add-on">
            <i data-time-icon="icon-time" data-date-icon="icon-calendar"></i>
          </span>
        </div>
      </div>
  </form>

  </div>
  </body>

</html>
/* Put your css in here */