test.rb

  def test_timestamp_with_zone_values_without_rails_time_zone_support
    p @connection.execute('SHOW TIME ZONE', 'SCHEMA').first["TimeZone"]
    with_timezone_config default: :local, aware_attributes: false do
      @connection.reconnect!
      @connection.execute("SET time zone 'America/Jamaica'", 'SCHEMA')

      @first_timestamp_with_zone = PostgresqlTimestampWithZone.find(1)
      assert_equal Time.utc(2010,1,1, 11,0,0), @first_timestamp_with_zone.time
      assert_instance_of Time, @first_timestamp_with_zone.time
      p @connection.execute('SHOW TIME ZONE', 'SCHEMA').first["TimeZone"]
    end
  ensure
    @connection.reconnect!
    p @connection.execute('SHOW TIME ZONE', 'SCHEMA').first["TimeZone"]
  end

"UTC"
"America/Jamaica"
"UTC"