Rental deprec for an appliance, it asks the business % of 2019 usage. If the unit & $1000 stove was rented in Sept would it be $333? the unit has been forsale since July.

The appliance is 100% in a rental property. You are not moving a stove back and forth for personal use. Put the dates into the program, let the program calculate the depreciation on the full 100% amount for the time period.

Further, if you purchased the stove in 2019 you may be able to expense the entire $1,000 (i.e., deduct the full amount) using the de minimis safe harbor election.