An Angular filter for outputting the date suffix - th, st, nd, rd

dateSuffixFilter.js

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

app.filter('dateSuffix', function ($filter) {
    var suffixes = ["th", "st", "nd", "rd"];
    return function (input) {
        var dtfilter = $filter('date')(input, 'dd');
        var day = parseInt(dtfilter, 10);
        var relevantDigits = (day < 30) ? day % 20 : day % 30;
        var suffix = (relevantDigits <= 3) ? suffixes[relevantDigits] : suffixes[0];
        return suffix;
    };
});

app.controller('Ctrl', ['$scope', function ($scope) {
    $scope.theDate = new Date();
}]);

usage.html

<span>{{ theDate | date:'MMMM dd' }}{{ theDate | dateSuffix }}</span>