title: How to use NSTimeZone -timeZoneWithName: with a city name from Rails ActiveSupport?
body: <p>If I only have the city name like <em>Bangkok</em> or <em>Tokyo</em>, how can I supply a timezone parameter in
  <code>[NSTimeZone timeZoneWithName:@"Asia/Tokyo"]</code> where it also has continent and slash in front of city?</p>
  
  <p>I already tried <code>[NSTimeZone timeZoneWithName:@"Tokyo"]</code>, it doesn't work.</p>