reconfigure_connection_timezone

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 1038
        def reconfigure_connection_timezone
          variables = @config.fetch(:variables, {}).stringify_keys

          # If it's been directly configured as a connection variable, we don't
          # need to do anything here; it will be set up by configure_connection
          # and then never changed.
          return if variables["timezone"]

          # If using Active Record's time zone support configure the connection
          # to return TIMESTAMP WITH ZONE types in UTC.
          if default_timezone == :utc
            internal_execute("SET SESSION timezone TO 'UTC'")
          else
            internal_execute("SET SESSION timezone TO DEFAULT")
          end
        end