When,according to Wisconsin law,do tenants have to give their 30 day notice?

Tenants have to give a 30 day notice if they are on a written rental agreement based month to month, or if they have no written agreement but paymnet is based on monthly.

If you have a lease, you are tied to the terms of the lease.
If you are on weekly rental agreements then normally the 30 day notice is not enforcable.

when,according to wisconsin law,do tenants have to give their 30 day notice?
There is an excellent website that lists copies of the state's landlord tenant law. Try going to MrLandlord.com to get a copy of the revised code for your state.