List a specific date that the tenancy ends. In your case, October 31, 2017. In your notice to the tenant do not address how many days notice this is.
Trying to read between the lines of your question it sounds to me as though you want to tell the tenant (or believe it is a requirement to tell the tenant) how many days notice are being given. I have never seen a state require that a certain number of days notice be given. Only that "at least" a certain number of days notice be given. Meaning you can give more notice but not less notice.