For purposes of this section, the taxpayer shall be deemed to have used a dwelling unit for personal purposes for a day if, for any part of such day, the unit is used—
(A)
for personal purposes by the taxpayer or any other person who has an interest in such unit, or by any member of the family (as defined in section 267(c)(4)) of the taxpayer or such other person;
(B)
by any individual who uses the unit under an arrangement which enables the taxpayer to use some other dwelling unit (whether or not a rental is charged for the use of such other unit); or
(C)
by any individual (other than an employee with respect to whose use section 119 applies), unless for such day the dwelling unit is rented for a rental which, under the facts and circumstances, is fair rental.
