es6.date.to-iso-string.js 1009 Bytes
'use strict';
// 20.3.4.36 / 15.9.5.43 Date.prototype.toISOString()
var $export = require('./_export')
  , fails   = require('./_fails')
  , getTime = Date.prototype.getTime;

var lz = function(num){
  return num > 9 ? num : '0' + num;
};

// PhantomJS / old WebKit has a broken implementations
$export($export.P + $export.F * (fails(function(){
  return new Date(-5e13 - 1).toISOString() != '0385-07-25T07:06:39.999Z';
}) || !fails(function(){
  new Date(NaN).toISOString();
})), 'Date', {
  toISOString: function toISOString(){
    if(!isFinite(getTime.call(this)))throw RangeError('Invalid time value');
    var d = this
      , y = d.getUTCFullYear()
      , m = d.getUTCMilliseconds()
      , s = y < 0 ? '-' : y > 9999 ? '+' : '';
    return s + ('00000' + Math.abs(y)).slice(s ? -6 : -4) +
      '-' + lz(d.getUTCMonth() + 1) + '-' + lz(d.getUTCDate()) +
      'T' + lz(d.getUTCHours()) + ':' + lz(d.getUTCMinutes()) +
      ':' + lz(d.getUTCSeconds()) + '.' + (m > 99 ? m : '0' + lz(m)) + 'Z';
  }
});