My tenant is on a periodic tenancy and called yesterday to inform me that he is giving me 30 days notice to move. As I understand it he needs to give at least a calendar month from the day before the rent is due.
The rent is due on the 15th of each month. Therefore if he gives me notice on 7th Jan he is liable to pay rent up to 14th Feb.
having not seen your AST which should be 6 weeks (usually) then they are all pro-rata hence your scenario given herein would be correct if the AST stated 4 weeks notice etc, in other words, 4 weeks notice can end up being 7 weeks notice as if they gave you notice after the 15th then they would be legally liable for almost 2 months if you understand.
If your tenancy is periodic, then the tenant’s notice should expire on the final day of a rental period. However, if you mutually agree a different day to terminate the tenancy, then that is fine. Anything is possible with mutual written agreement.
It is important to note that the day the rent is due may not be the same day as the start/end of the rental period. The standard minimum notice that a tenant can give to terminate the tenancy is one month.