For you who are a tenant, one (1) calendar month's notice period applies.
Example of notice period:
A tenant terminates his contract 4th of November, with 1 calendar month in notice period, the tenant will need to pay full rent for December as well (until 31st of December.)
If the same tenant instead would terminate the contract 30th of November, the tenant would still pay to 31st of December, as there needs to be one completely full month of payment in addition to whatever days are remaining in the current month where termination was sent.
Do not mistake 1 calendar months’ notice period for 30 days.