Do you have to give landlord 30 day notice on a month to month tenancy in Indiana

No, you need one CALENDAR months notice. Therefore, if you give notice today it would be effective at the end of October.

Indiana Code 32-7-1-3
IC 32-7-1-3 Sec. 3. All tenancies from year to year, may be
Determined by at least three (3) months' notice given to the
Tenant prior to the expiration of the year; and in all tenancies
Which, by agreement of the parties, express or implied, are from one period to another, of less than three (3) months' duration, a notice equal to the interval between such periods shall be sufficient.