When the landlord has decided to terminate their resident's tenancy, they have to properly serve them a notice to vacate:
If tenancy is less than 12 months, the landlord serves a 30 day notice to vacate.
If tenancy is over 12 months, the landlord serves a 60 day notice to vacate.
The landlord may serve the notice to the resident by:
Personal service: You or someone else gives the notice directly to the tenant in person.
Substituted service: If the tenant is not home, you can leave the notice with a member of the household, at least 18 years old, where the tenant lives AND then mail a second copy to the tenant at the property.
Posting and mailing ("nail and mail") service: If there is no one home to leave the papers with, you can tape or nail the notice to the front door or somewhere where it can be seen easily AND send a copy by mail to the tenant at the property.
When a resident decides to terminate tenancy, the must do so with a 30 day written notice to the landlord. As long as their contract is expired or expire on move out date, they can give notice at any time of the month - it does not have to be on the 1st.