I am using bootstrap date-picker in my angular application. However when I select a date from that date-picker underlying ng-model that I have bind gets updated I want that
The format specified through datepicker-popup is just the format for the displayed date. The underlying ngModel is a Date object. Trying to display it will show it as it's default, standard-compliant rapresentation.
You can show it as you want by using the date filter in the view, or, if you need it to be parsed in the controller, you can inject $filter in your controller and call it as $filter('date')(date, format). See also the date filter docs.