An angular filter calculating the the days between two dates.

days-between-dates.js

angular.module('eds.daysBetweenDates', []).filter('daysBetweenDates', function() {
	return function(startDate, endDate) {
		if (startDate && endDate) {
			var start = moment(startDate).hour(0).minute(0).second(0).millisecond(0);
			var end = moment(endDate).hour(0).minute(0).second(0).millisecond(0).add('day', 1);
			return moment(end).diff(start, 'days')
		} else {
			return 0;
		}
	}
});

days-between-dates.spec.js

describe('filter', function() {

	beforeEach(module('eds.daysBetweenDates'));

	describe('daysBetweenDates', function() {

		it('should be 1', inject(function(daysBetweenDatesFilter) {
			var start = new Date();
			var end = new Date();
			expect(daysBetweenDatesFilter(start, end)).toEqual(1);
		}));

		it('should be 2', inject(function(daysBetweenDatesFilter) {
			var start = moment().subtract(1, 'days').toDate();
			var end = new Date();
			expect(daysBetweenDatesFilter(start, end)).toEqual(2);
		}));

		it('should be 8', inject(function(daysBetweenDatesFilter) {
			var start = new Date();
			var end = moment().add(1, 'weeks').toDate();
			expect(daysBetweenDatesFilter(start, end)).toEqual(8);
		}));

		it('should be 2', inject(function(daysBetweenDatesFilter) {
			var start = moment('2012-01-01 01:00:00').toDate();
			var end = moment('2012-01-02 23:00:00').toDate();
			expect(daysBetweenDatesFilter(start, end)).toEqual(2);
		}))

	});

});