Just remember, if the renter moved out in 2017 and you sold it in 2018, then your days of personal use is a big, fat ZERO, and days rented will be 1 (ONE). The fact you show no income in 2018 for that one day is no big deal. Consider this:
Tenant rent period runs from the 2nd day of the month, through the first day of the next month. So they pay the month's rent on Dec 2nd. The last day they can occupy the house will be Jan 1 of the following year. So it's rented for one single day in 2018 with no rental income reported in 2018, because that one day was included in the month's rent that was paid on Dec 2 in the prior year.
That's just the analogy. I don't know anyone who has a renter move out and then closes on the sale within 30 days. Not impossible of course. But extremely rare.
