A landlord may only give notice to vacate in certain circumstances.
When a fixed term lease has a clause allowing the landlord to end it before the end of the fixed term by giving notice.
When a lease without a fixed term (periodic) or in the absence of a lease by giving three months’ notice.
No notice is required when a fixed term lease is coming to the end of the term.  Fixed terms leases are assumed to be ending, unless both parties agree otherwise.  We recommend seeking agreement in advance if you wish to remain in the property and getting it in writing.
If a landlord continues to accept rent after a fixed term lease expires, it becomes a periodic lease.