Date.ISO8601.js

(function () {
  "use strict";
  
  var TO_ISO8601_DEFAULTS = {
    year: true,
    date: true,
    time: true,
    seconds: true,
    milliseconds: true,
    utc: false,
    zone: true
  };
  
  function zeroPad(oInt) {
    return (oInt < 10 ? "0" : "") + oInt;
  }
  
  Date.prototype.setISO8601 = (function () {
    var REG_EXP = /(\d\d\d\d)(?:\-?(\d\d)(?:\-?(\d\d)(?:[T ](\d\d)(?::?(\d\d)(?::?(\d\d)(?:\.(\d+))?)?)?(?:Z|(?:([\-+])(\d\d)(?::?(\d\d))?)?)?)?)?)?/;
    return function (string) {
      var d, offset, date, time;

      d    = string.match(REG_EXP);
      offset  = 0;
      date  = new Date(d[1], 0, 1);

      if (d[2]) {
        date.setMonth(d[2] - 1);
      }
      if (d[3]) {
        date.setDate(d[3]);
      }
      if (d[4]) {
        date.setHours(d[4]);
      }
      if (d[5]) {
        date.setMinutes(d[5]);
      }
      if (d[6]) {
        date.setSeconds(d[6]);
      }
      if (d[7]) {
        date.setMilliseconds(Number("0." + d[7]) * 1000);
      }
      if (d[8]) {
        offset = (Number(d[9]) * 60) + Number(d[10]);
        offset *= ((d[8] === '-') ? 1 : -1);
      }
      offset -= date.getTimezoneOffset();
      time = Number(date) + (offset * 60 * 1000);
      this.setTime(time);
    };
  }());
  Date.prototype.toISO8601 = function (oConfig) {
    var result = "", i, z, config = {};
    
    if (! oConfig) {
      config = TO_ISO8601_DEFAULTS;
    }
    else {
      for (i in TO_ISO8601_DEFAULTS) {
        if (TO_ISO8601_DEFAULTS.hasOwnProperty(i)) {
          config[i] = (typeof oConfig[i] !== "undefined") ? oConfig[i] : TO_ISO8601_DEFAULTS[i];
        }
      }
    }
    if (config.year) {
      result += (this.utc ? this.getUTCFullYear() : this.getFullYear());
    }
    if (config.year && config.date) {
      result += '-';
    }
    if (config.date) {
      result += zeroPad((this.utc ? this.getUTCMonth() : this.getMonth()) + 1) + '-' + zeroPad(this.utc ? this.getUTCDate() : this.getDate());
    }
    if (config.date && config.time) {
      result += "T";
    }
    if (config.time) {
      result += zeroPad((this.utc ? this.getUTCHours() : this.getHours())) + ':' + zeroPad(this.utc ? this.getUTCMinutes() : this.getMinutes());
      
      if (config.seconds) {
        result += ':' + zeroPad(this.utc ? this.getUTCSeconds() : this.getSeconds());
        
        if (config.milliseconds) {
          result += '.' + zeroPad(this.utc ? this.getUTCMilliseconds() : this.getMilliseconds());
        }
      }
      if (config.zone && config.utc) {
        result += '+0:00';
      }
      else if (config.zone) {
        z = this.getTimezoneOffset() / 60;
        result += ((z > 0) ? '+' : '') + Math.floor(z) + ':' + zeroPad((z - Math.floor(z)) * 100 / 60);
      }
    }
    
    return result;
  };
  Date.ISO8601 = function (string) {
    var d = new Date();
    d.setISO8601(string);
    return d;
  };
}());