> Following it through the system, only sys_settimeofday and sys_gettimeofday
> in kern_time.c seem to use the tz variable that holds their values, and I
> guess it only makes a difference if the time of day is gotten before it gets
> setten..  I can't quite work that out though (I thought it was all done in
> /etc/localtime but that might come later)

It is obsolete. All userland utilities should use `/etc/localtime' (see
ctime(3) et.al.). [gs]ettimeofday(2) also warns that the `struct timezone'
argument is no longer used. The kernel still maintains some degree of
compatibility, but, as you note, no sane kernel configuration file actually
specifies its geographical whereabouts, the information might not be
accurate.

I guess it's time to make the kernel config options entirely optional.

-pk