title: Are timezones with the same GMT offset different in any way?
body: <p>Windows asks users to choose from about <a href="http://unattended.sourceforge.net/timezones.php" rel="nofollow">200 timezones</a>, when there are actually only 25 GMT offsets. (see below)</p>
  
  <p>Can I ask users in my app to chose from these alone? Is there any difference between timezones that have the same GMT offset? (<strong>eg:</strong> Mountain Standard Time <strong>vs.</strong> Mexico Standard Time 2)</p>
  
  <pre><code>-12.0,GMT -12:00,Eniwetok, Kwajalein
  -11.0,GMT -11:00,Midway Island, Samoa
  -10.0,GMT -10:00,Hawaii
  -9.0,GMT -9:00,Alaska
  -8.0,GMT -8:00,Pacific Time, US &amp; Canada
  -7.0,GMT -7:00,Mountain Time, US &amp; Canada
  -6.0,GMT -6:00,Central Time, US &amp; Canada, Mexico City
  -5.0,GMT -5:00,Eastern Time, US &amp; Canada, Bogota, Lima
  -4.0,GMT -4:00,Atlantic Time, Canada, Caracas, La Paz
  -3.5,GMT -3:30,Newfoundland
  -3.0,GMT -3:00,Brazil, Buenos Aires, Georgetown
  -2.0,GMT -2:00,Mid-Atlantic
  -1.0,GMT -1:00 hour,Azores, Cape Verde Islands
  0.0,GMT,Western Europe Time, London, Lisbon, Casablanca
  1.0,GMT +1:00 hour,Brussels, Copenhagen, Madrid, Paris
  2.0,GMT +2:00,Kaliningrad, South Africa
  3.0,GMT +3:00,Baghdad, Riyadh, Moscow, St. Petersburg
  3.5,GMT +3:30,Tehran
  4.0,GMT +4:00,Abu Dhabi, Muscat, Baku, Tbilisi
  4.5,GMT +4:30,Kabul
  5.0,GMT +5:00,Ekaterinburg, Islamabad, Karachi, Tashkent
  5.5,GMT +5:30,Bombay, Calcutta, Madras, New Delhi
  5.75,GMT +5:45,Kathmandu
  6.0,GMT +6:00,Almaty, Dhaka, Colombo
  7.0,GMT +7:00,Bangkok, Hanoi, Jakarta
  8.0,GMT +8:00,Beijing, Perth, Singapore, Hong Kong
  9.0,GMT +9:00,Tokyo, Seoul, Osaka, Sapporo, Yakutsk
  9.5,GMT +9:30,Adelaide, Darwin
  10.0,GMT +10:00,Eastern Australia, Guam, Vladivostok
  11.0,GMT +11:00,Magadan, Solomon Islands, New Caledonia
  12.0,GMT +12:00,Auckland, Wellington, Fiji, Kamchatka
  </code></pre>