Convert an ISO 8601 Date String to / from a Native AS3 Date Object

While making some improvements to my ilist metadata (iTunes MPEG4 style metadata) classes I ended up needing to convert an ISO 8601 date and time string to a native AS3 Date object and vice versa.

An ISO 8601 date and time string comes in two flavors, basic and extended. As you can see below, the basic format simply eschews dashes and colons in favor of a more compact syntax.

• Basic – 20090221T090000Z
• Extended – 2009-02-21T09:00:00Z

The standard requires a fixed number of digits to represent a date (8 digits) or a time (6 digits). When fewer digits are needed to represent a date / time the number must be padded with leading zeros. The Z at the end of the string designates the UTC “Zulu” timezone (GMT or so called universal time).

I took a quick buzz around the interwebs, but couldn’t find an AS3 lib that could convert one of these strings into a date object or take a date object and have it generate a correctly formatted string, so, you guessed it–I spent my Sunday evening whipping together a utility class that will do the trick (download the source here).

I’m not claiming compliance with every nook and cranny of the spec, but it covers the fundamentals decently. Hand the util an AS3 Date object and you can generate a date, time or date + time in the basic or extended format. You can also parse a basic / extended date, time or date + time string and have an AS3 Date object returned with the appropriate UTC values set on it.

Here’s what the basic usage would look like for a date + time scenario:

// instantiate a ISO8601Util object
 var util:ISO8601Util = new ISO8601Util();
// parse a date + time string into an AS3 Date  - takes either a basic or 
// extended representation         
var date:Date = util.parseDateTimeString( "2009-02-21T09:07:59Z" );
 
// to turn a date into an ISO 8601 date + time representation grab a date object
var currentdate:Date = new Date();
// create a string with the extended or basic format
var extended:String = util.formatExtendedDateTime( currentdate )
var basic:String = util.formatBasicDateTime( currentdate );

Hopefully, I’m now the only poor bastard who has to do this!