Make jQuery or PHP Session data available for other visitors with random (secret) link

I need to store data in an session and make it available for other users.

I thought about to store that data in an Session, generate a random Link, which user 1 can send to user 2. The Session should expire after 3 Month.

The Sessionname is the random code i generate which is simluar to the code i send with POST to receive it on the Secretlink with $_GET.

Is this working in general or am i on the wrong track? Can i store a Session even when the user1 left the website or will the session be terminated?

I also need to set the Session via jQuery, but i couldn´t find anything about expiration time of a session.

I already did it with a Cookie, but of course that´s not working with user 2.