config.time_zone not setting default_timezone for AR, causing errors with Postgres

It appears that setting Rails::Application.config.time_zone (in application.rb) does not set ActiveRecord::Base.default_timezone.

If I set the config.time_zone in my application.rb to, for example, Central Time, then firing up the console shows:

    > Rails::application.config.time_zone
   => "Central Time (US & Canada)"
    > Rails::Application.config.active_record.default_timezone
   => nil

That may be expected behavior, and according to the postgres adapter, a nil value would cause activerecord to read the timezone from the default value of the postgres database, as per the following code (line 956):

      if ActiveRecord::Base.default_timezone == :utc
        execute("SET time zone 'UTC'")
      elsif @local_tz
        execute("SET time zone '#{@local_tz}'")
      end

However, the problem is that somewhere in the ActiveRecord stack, before calling the postgres adapter, the value of AR::Base.default_timezone is being changed from nil to 'utc'. This causes AR to try to execute the postgres command 'set time zone 'UTC'', which on a system where 'utc' is not recognized, will give the following error:

    PGError: ERROR:  unrecognized time zone name: "UTC"
    : SET time zone 'UTC'

(This can easily go unnoticed, because in most cases 'UTC' is valid. I discovered this problem, after much agony and hair pulling, on a freebsd system where it turns out postgres would only accept 'etc/utc' as a valid timezone, not 'utc'.)

I can verify that AR::Base.default_timezone is being set to 'utc' by checking the value just before the above lines, in the postgresql_adapter.rb:

      puts ActiveRecord::Base.default_timezone
      puts Rails::Application.config.time_zone          

      if ActiveRecord::Base.default_timezone == :utc
        execute("SET time zone 'UTC'")
      elsif @local_tz
        execute("SET time zone '#{@local_tz}'")
      end

The above, with config.time_zone set to Central Time, and AR::Base.default_timezone not set in application.rb, will return:

     utc
     Central Time (US & Canada)

So it seems that config.time_zone is not having an effect on AR::Base.default_timezone.