Article 450 of Civil Code says
When the lease is made for a definite period, the lease terminates at the end of such period.
If no such period has been specified for the termination of the lease, each party may terminate it at any time. However, if customs is in favor of the lessee, such customs shall be followed.
To terminate a lease as specified in the preceding paragraph a notice shall be given in advance according to customs, but if the rental of a real property is payable weekly, fortnightly or monthly, termination is effective only at the end of the calendar week, or fortnight, or month, and a notice shall be given at least one week or fortnight or month in advance.