Days of personal use will practically always be zero. The days of personal use is the number of days you used to property or space for personal use *AFTER* you converted it to a rental.
So if you rented out 1 room in your house and you converted that one room to a rental on Aug 1 of the tax year and you "NEVER" used that room for your personal use after that date, your days of personal use is ZERO. Doesn't matter if the room sat empty and you didn't actually get a renter in there for three months after the date of conversion. So long as you did not use the room for personal use for one single day after the date of conversion, the days of personal use is ZERO.
Additionally, if you converted the room to a rental on Aug 1, that means it was classified as a rental from Aug 1 through Dec 31 which is 151 days. That means it is physically impossible for you to have more than 150 days of personal use. (If you claim the entire 151 days of personal use, then you can't classify it as a rental.)
