Automatic ISO 8601 conversion in Javascript

iso9601DateConv.js

$.ajaxSetup({ 
            converters: { "text json": function (jsonString) {
                var res = JSON.parseWithDate(jsonString);
 
                if (res && res.hasOwnProperty("d"))
                    res = res.d;
                return res;
            } }
});

/*
Ripped from ServiceProxy.js  
Version 0.981 - 4/5/11

(c) 2008-2011 Rick Strahl, West Wind Technologies 
www.west-wind.com

Licensed under MIT License
http://en.wikipedia.org/wiki/MIT_License
*/
    if (this.JSON && !this.JSON.parseWithDate) {
    //Original reISO regex replaced with one pulled from XDate.js
    var reISO = /^(\d{4})(-(\d{2})(-(\d{2})([T ](\d{2}):(\d{2})(:(\d{2})(\.(\d+))?)?(Z|(([-+])(\d{2})(:?(\d{2}))?))?)?)?)?$/
    var reMsAjax = /^\/Date\((d|-|.*)\)[\/|\\]$/;

    JSON.parseWithDate = function (json) {
        /// <summary>
        /// parses a JSON string and turns ISO or MSAJAX date strings
        /// into native JS date objects
        /// </summary>    
        /// <param name="json" type="var">json with dates to parse</param>        
        /// </param>
        /// <returns type="value, array or object" />
        try {
            var res = JSON.parse(json,
            function (key, value) {
                if (typeof value === 'string') {

                    var a = reISO.exec(value);
                    if (a) {
                        var d = new Date(Date.UTC(
                            a[1],
                            a[3] ? a[3] - 1 : 0,
                            a[5] || 1,
                            a[7] || 0,
                            a[8] || 0,
                            a[10] || 0,
                            a[12] ? Number('0.' + a[12]) * 1000 : 0
                        ));

                        if (a[13]) { // has gmt offset or Z
                            if (a[14]) { // has gmt offset
                                d.setUTCMinutes(
                                    d.getUTCMinutes() + (a[15] == '-' ? 1 : -1) * (Number(a[16]) * 60 + (a[18] ? Number(a[18]) : 0))
                                );
                            }
                        }

                        return d;
                    }

                    a = reMsAjax.exec(value);
                    if (a) {
                        var b = a[1].split(/[-+,.]/);
                        return new Date(b[0] ? +b[0] : 0 - +b[1]);
                    }
                }
                return value;
            });
            return res;
        } catch (e) {
            // orignal error thrown has no error message so rethrow with message
            throw new Error("JSON content could not be parsed");
            return null;
        }
    };

    JSON.dateStringToDate = function (dtString) {
        /// <summary>
        /// Converts a JSON ISO or MSAJAX string into a date object
        /// </summary>    
        /// <param name="" type="var">Date String</param>
        /// <returns type="date or null if invalid" /> 
        var a = reISO.exec(dtString);
        if (a) {
            var d = new Date(Date.UTC(
                a[1],
                a[3] ? a[3] - 1 : 0,
                a[5] || 1,
                a[7] || 0,
                a[8] || 0,
                a[10] || 0,
                a[12] ? Number('0.' + a[12]) * 1000 : 0
            ));

            if (a[13]) { // has gmt offset or Z
                if (a[14]) { // has gmt offset
                    d.setUTCMinutes(
                        d.getUTCMinutes() + (a[15] == '-' ? 1 : -1) * (Number(a[16]) * 60 + (a[18] ? Number(a[18]) : 0))
                    );
                }
            }

            return d;
        }

        a = reMsAjax.exec(dtString);
        if (a) {
            var b = a[1].split(/[-,.]/);
            return new Date(+b[0]);
        }

        return null;
    };
}