[TUHS] Date madness

[Noel Chiappa]

    > Guess the date code is probably missing the '400 year' exception.

So, I looked at the code, and the bug is not obvious. (The routine for
detecting leap years in V6's ctime.c is so minimalistic it actually works for
2000!)

The version I'm currently running had been worked on some, to have a hack fix
for the overflow of the number of 8-hour periods since the epoch ("hack" since
the 'fixed' version will break in 2029 or so), and I was worried that 'fix'
was wrong and caused the week-day problem, but I don't think so.

    Noel