I've known that AS3 included some formatter classes, including DateFormatter, for some time now but didn't have cause to use them until today. I'm not sure if its laziness or that I just don't understand some level of abstraction Adobe was striving for with their implementation, but I found it maddeningly complicated to use. I was expecting something like php's date(), which usually looks something like this:

$formattedDate = date($myDateString, 'd/m/Y');

Well, you can imagine my horror (exaggerate much?) when I discovered that the same functionality in AS3 looked like this:

var df:DateFormatter = new DateFormatter();
df.formatString = "MM/DD/YYYY";
var formattedDate:String = df.format(myUnformattedString);

My solution? QuickDateFormatter, whose usage looks like this:

var formattedDate:String = QuickDateFormatter.format(myUnformattedString, "MM/DD/YYYY");

Much quicker and cleaner, specially made for us lazy folk. I suppose to match the robustness of the built-in DateFormatter I would need to add some error handling but I am not really worried about that. This is meant for cases where you know the input is a valid date but you need to alter the formatting. You can grab the source here or simply copy and paste from below.

package com.fmr.utils
{
    import mx.formatters.DateFormatter;

    public class QuickDateFormatter
    {
        public static function format(str_dateString:String, str_dateFormat:String):String
        {
            var f:DateFormatter = new DateFormatter();
            f.formatString = str_dateFormat;
            return f.format(str_dateString);
        }
    }
}

Enjoy!