Taxes: Owner Occupied to Rental Property During Same Year

[Jared Christian]

We moved into our owner-occupied duplex in June 2016, and were immediately renting the other unit out. We were only there for four months and then suddenly had to move out of state, therefore, causing us to rent both units out. With respects to taxes on this property (I apologize for my ignorance), do I recognize it as a primary residence for the four months we lived there and then recognize it as a rental property for the other three months, or will it always be considered a rental property from day one? 

Also worth noting, for the four months we lived there we never received any actual rental income, as the small amount we received from the tenant in the other unit just contributed towards the mortgage. We paid the remaining balance. 

Thank you in advance for your advice!