util.js

define([
	'exports'
], function (exports) {
	exports.toRelativeDate = function (isoString) {
		var date = new Date((isoString || '').replace(/-/g, '/').replace(/[TZ]/g, ' '));
		var now = Date.now() + (new Date()).getTimezoneOffset() * 60000;
		var diff = (now- date.getTime()) / 1000;
		var dayDiff = Math.floor(diff / 86400);

		if (isNaN(dayDiff) || dayDiff < 0 || dayDiff >= 31) {
			return;
		}

		if (diff < 60) {
			return 'just now';
		}

		if (diff < 120) {
			return '1 minute ago';
		}

		if (diff < 3600) {
			return Math.floor(diff / 60) + ' minutes ago';
		}

		if (diff < 7200) {
			return '1 hour ago';
		}

		if (diff < 86400) {
			return Math.floor(diff / 3600) + ' hours ago';
		}

		if (dayDiff === 1) {
			return 'Yesterday';
		}

		if (dayDiff < 7) {
			return dayDiff + ' days ago';
		}

		if (dayDiff < 31) {
			return Math.ceil(dayDiff / 7) + ' weeks ago';
		}
	};
});