Special rules
For purposes of this section—
(1)
(1)#
the status as husband and wife of two individuals having taxable years beginning on the same day shall be determined—
(A) if both have the same taxable year—as of the close of such year; or
(B) if one dies before the close of the taxable year of the other—as of the time of such death;
(2)#
an individual who is legally separated from his spouse under a decree of divorce or of separate maintenance shall not be considered as married; and
(3)#
if a joint return is made, the tax shall be computed on the aggregate income and the liability with respect to the tax shall be joint and several.