zone_utc?

# File lib/time.rb, line 86
    def zone_utc?(zone)
      # * +0000 means localtime. [RFC 2822]
      # * GMT is a localtime abbreviation in Europe/London, etc.
      if /\A(?:-00:00|-0000|-00|UTC|Z|UT)\z/i =~ zone
        true
      else
        false
      end
    end