What to do with an existing session during authorization?

Question

PHP

An anonymous user visits the site, a session starts, let's say the session lifetime is set to a week in the settings.
The user logs in, what to do with the session next?
We use the same session and fill with data?
How then to adjust session lifetime? let's say tomorrow it ends, and the user just logged in,
or do we kill the session and start it over again? Or just start over?

Answer 1

An anonymous user visits the site, a session starts

it should not be