Normally, landlords require tenants to pay the first month's rent before turning over possession of the rental property. Whether or not that first payment is pro-rated for a lease starting on any day other than the first of the month is an issue that should be discussed with the landlord prior to that initial payment. Thereafter, rent is normally due on the first of each subsequent month, although most leases provide a grace period, usually five days, before late charges are assessed.
Absent a written lease agreement, the rent would typically be due at the first of the month. Unlike mortgage payments, which are paid in arrears, rent payments are paid in advance.
However, if there is a written lease agreement that states when the rent is due, then this provision will be controlling. Even though you're on a month-to-month tenancy, its still a good idea to have a lease agreement drafted to protect yourself and to avoid possible disputes.
The above response is for informational and educational purposes only and should not be construed as legal advice. No attorney-client relationship is formed through the use of this website. Please consult an attorney licensed to practice law in your state.