function mktime () {
  // http://kevin.vanzonneveld.net
  // +   original by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
  // +   improved by: baris ozdil
  // +      input by: gabriel paderni
  // +   improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
  // +   improved by: FGFEmperor
  // +      input by: Yannoo
  // +   bugfixed by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
  // +      input by: jakes
  // +   bugfixed by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
  // +   bugfixed by: Marc Palau
  // +   improved by: Brett Zamir (http://brett-zamir.me)
  // +      input by: 3D-GRAF
  // +   bugfixed by: Brett Zamir (http://brett-zamir.me)
  // +      input by: Chris
  // +    revised by: Theriault
  // %        note 1: The return values of the following examples are
  // %        note 1: received only if your system's timezone is UTC.
  // *     example 1: mktime(14, 10, 2, 2, 1, 2008);
  // *     returns 1: 1201875002
  // *     example 2: mktime(0, 0, 0, 0, 1, 2008);
  // *     returns 2: 1196467200
  // *     example 3: make = mktime();
  // *     example 3: td = new Date();
  // *     example 3: real = Math.floor(td.getTime() / 1000);
  // *     example 3: diff = (real - make);
  // *     results 3: diff < 5
  // *     example 4: mktime(0, 0, 0, 13, 1, 1997)
  // *     returns 4: 883612800
  // *     example 5: mktime(0, 0, 0, 1, 1, 1998)
  // *     returns 5: 883612800
  // *     example 6: mktime(0, 0, 0, 1, 1, 98)
  // *     returns 6: 883612800
  // *     example 7: mktime(23, 59, 59, 13, 0, 2010)
  // *     returns 7: 1293839999
  // *     example 8: mktime(0, 0, -1, 1, 1, 1970)
  // *     returns 8: -1
  var d = new Date(),
    r = arguments,
    i = 0,
    e = ['Hours', 'Minutes', 'Seconds', 'Month', 'Date', 'FullYear'];

  for (i = 0; i < e.length; i++) {
    if (typeof r[i] === 'undefined') {
      r[i] = d['get' + e[i]]();
      r[i] += (i === 3); // +1 to fix JS months.
    } else {
      r[i] = parseInt(r[i], 10);
      if (isNaN(r[i])) {
        return false;
      }
    }
  }

  // Map years 0-69 to 2000-2069 and years 70-100 to 1970-2000.
  r[5] += (r[5] >= 0 ? (r[5] <= 69 ? 2e3 : (r[5] <= 100 ? 1900 : 0)) : 0);

  // Set year, month (-1 to fix JS months), and date.
  // !This must come before the call to setHours!
  d.setFullYear(r[5], r[3] - 1, r[4]);

  // Set hours, minutes, and seconds.
  d.setHours(r[0], r[1], r[2]);

  // Divide milliseconds by 1000 to return seconds and drop decimal.
  // Add 1 second if negative or it'll be off from PHP by 1 second.
  return (d.getTime() / 1e3 >> 0) - (d.getTime() < 0);
}

mktime(14, 10, 2, 2, 1, 2008);

1201875002

mktime(0, 0, 0, 0, 1, 2008);

1196467200