Javascript Date setISO8601(dString)

Date.prototype.setISO8601 = function(dString) {
 var regexp = /(\d\d\d\d)(-)?(\d\d)(-)?(\d\d)(T)?(\d\d)(:)?(\d\d)(:)?(\d\d)(\.\d+)?(Z|([+-])(\d\d)(:)?(\d\d))/;
 if (dString.toString().match(new RegExp(regexp))) {
  var d = dString.match(new RegExp(regexp));
  var offset = 0;
  this.setUTCDate(1);/*from www  . ja  va2s. c om*/
  this.setUTCFullYear(parseInt(d[1], 10));
  this.setUTCMonth(parseInt(d[3], 10) - 1);
  this.setUTCDate(parseInt(d[5], 10));
  this.setUTCHours(parseInt(d[7], 10));
  this.setUTCMinutes(parseInt(d[9], 10));
  this.setUTCSeconds(parseInt(d[11], 10));
  if (d[12]) {
   this.setUTCMilliseconds(parseFloat(d[12]) * 1000);
  } else {
   this.setUTCMilliseconds(0);
  }
  if (d[13] != 'Z') {
   offset = (d[15] * 60) + parseInt(d[17], 10);
   offset *= ((d[14] == '-') ? -1 : 1);
   this.setTime(this.getTime() - offset * 60 * 1000);
  }
 } else {
  this.setTime(Date.parse(dString));
 }
 return this;
};