A couple of notes:
Merely because the property is rented for less than a year, does not make it a "vacation rental". The IRS, in fact, does not have an actual definition of "vacation rental".
The scenario set forth indicate that rental period was less than a year and that the property was converted to personal use for the last month of the tax year. As such, expenses not directly related to rental use (during the rental period) have to be prorated.
Further, depreciation is not a requirement; it is "allowed" per Section 167. Depreciation on property held for business use or for the production of income is recaptured based upon depreciation deductions allowed or allowable.
