Log connection time

Hello Igor,
Would it be possible to provide a variable that $connection_time for
that could be logged and that would provide the duration of a
If the connection time is longer than the keepalive_timeout then it
would have
the keepalive_timeout value otherwise it would have the value of when
connection was dropped.
I don’t know if this is possible but it would be great to have it
because it
would give an indication on how long readers stay on every page.

Thank you

Best Regards