Adds all of the attributes defined in RFC 5455

lib/timezone.js

@@ -6,7 +6,15 @@
  * @constructor ICalTimezone Timezone
  */
 var ICalTimezone = function(_data, calendar) {
-  var attributes;
+  var attributes = [
+    'tzid',      // REQUIRED, MUST NOT occur more than once
+    'last-mod',  // OPTIONAL, MUST NOT occur more than once
+    'tzurl',     // OPTIONAL, MUST NOT occur more than once
+    'standardc', // Either {s/d}c REQUIRED, MAY occur more than once
+    'daylightc', // Either {s/d}c REQUIRED, MAY occur more than once
+    'x-prop',    // OPTIONAL, MAY occur more than once
+    'iana-prop'  // OPTIONAL, MAY occur more than once
+  ];
 };
 
 module.exports = ICalTimezone;