What is the lifespan of a session ID?

when using a session id in the url, as to allow people to "save" a partially completed form, is there an expiration of that session id?

User can go back to the form anytime and continue working with the form. The last saved submission data will still be there. Please be noted that sessions do expire and if I am not wrong, the life of the session is 3 months which seems to be a reasonable time frame. But I think our developers has changed this to just one month.

Hope this will help. Let us know if you need further assistance.