You can specify a time unit after a time value 'X', such as Xw, Xd, Xh, Xm or Xs, to represent weeks (w), days (d), hours (h), minutes (m) and seconds (s), respectively. interval will be available
in controller $scope in ms.
<form class="col-md-6">
<legend>Simple example</legend>
<div class="form-group">
<input type="text" class="form-control" ng-model="interval" ng-interval>
</div>
<div class="form-group">
<label>Value in ms: </label> {{interval}}
</div>
</form>