Why is my custom date filter (angular) returning gobbledy-gook?

The markup (Jade)

.col-md-9
       | {{client.person.date_of_birth | date:'standardDate'}}

The filter (angular)

  .filter('standardDate', function($filter){
      var dateFilter = $filter('date');
      return function(date) {
        return dateFilter(date, 'MM dd yyyy');
      }
  })

The filtered date it returns:

0nStAMn16AMr16DAMte

When I use one of angular's preset date formatters (e.g. 'shortdate'), this works, suggesting the date param is not the problem.

No need to pass in the date filter, as your standardDate filter already brings in the $filter service and returns the filtered date all on its own.

So, your markup should look like this:

.col-md-9
       | {{client.person.date_of_birth | standardDate }}