In California, on a 6 month lease, what is the required notification time for a tenant to advise landlord he is moving out? The 6 months expired on June 1st - it is now June 7th and no rent or word from tenant. I emailed yesterday and called today - no return yet.

What does the lease say? Does the lease require notice of renewal? Generally, termination of a lease requires a 30 day notice, not matter what the term of the lease. So when you didn't hear from them by April 30 that they were not renewing the lease, then the assumption would be they will continue to reside.

Either a 30 day or a 60 day is the normal time listed in the lease.
So what does the lease say, that is the time required