of day, day of week, and season.
Fix the weekday predictions -- these seemed to be all bogus. The new
predictions seem to correspond with strftime() on Solaris and IRIX, so
I believe they are correct.
Get rid of the test for non-standard format %C returning "the same as
date(1)". This is hard to do reliably without opening a pipe to date,
and moreover, on IRIX 6.2, %C yields the Century. So we use that
instead. (We don't complain about this in non-verbose mode anyway.)
1. If a conversion isn't supported on the current platform, just
ignore it, unless running as a script (i.e. verbose)
2. Don't use time.time() and os.popen('date') to get the raw values.
These will always be different!