Does time() honor leap seconds?

[Steve Harrold]

Does time() honor leap seconds?

The value returned by time() is supposed to be the number of seconds since
midnight Jan 1, 1970.  

Does anyone know if leap-seconds are supposed to be accounted for in this
value, or is each year assumed to have the same length as any other year?

The question is prompted by the fact that one second was inserted at the
the end of 1989, _before_ 1990 began, by the international time-keeping
organizations.