/**
 * Date.parse with progressive enhancement for ISO 8601 <https://github.com/csnover/js-iso8601>
 * © 2011 Colin Snover <http://zetafleet.com>
 * Released under MIT license.
 */
(function (Date, undefined) {
    var origParse = Date.parse, numericKeys = [ 1, 4, 5, 6, 7, 10, 11 ];
    Date.parse = function (date) {
        var timestamp, struct, minutesOffset = 0;

        // ES5 §15.9.4.2 states that the string should attempt to be parsed as a Date Time String Format string
        // before falling back to any implementation-specific date parsing, so that’s what we do, even if native
        // implementations could be faster
        //              1 YYYY                2 MM       3 DD           4 HH    5 mm       6 ss        7 msec        8 Z 9 ±    10 tzHH    11 tzmm
        if ((struct = /^(\d{4}|[+\-]\d{6})(?:-(\d{2})(?:-(\d{2}))?)?(?:T(\d{2}):(\d{2})(?::(\d{2})(?:\.(\d{3}))?)?(?:(Z)|([+\-])(\d{2})(?::(\d{2}))?)?)?$/.exec(date))) {
            // avoid NaN timestamps caused by “undefined” values being passed to Date.UTC
            for (var i = 0, k; (k = numericKeys[i]); ++i) {
                struct[k] = +struct[k] || 0;
            }

            // allow undefined days and months
            struct[2] = (+struct[2] || 1) - 1;
            struct[3] = +struct[3] || 1;

            if (struct[8] !== 'Z' && struct[9] !== undefined) {
                minutesOffset = struct[10] * 60 + struct[11];

                if (struct[9] === '+') {
                    minutesOffset = 0 - minutesOffset;
                }
            }

            timestamp = Date.UTC(struct[1], struct[2], struct[3], struct[4], struct[5] + minutesOffset, struct[6], struct[7]);
        }
        else {
            timestamp = origParse ? origParse(date) : NaN;
        }

        return timestamp;
    };
}(Date));
