short-weekday-name -- Return the short (English) names for date quantities
short-weekday-name( weekday, name);
short-month-name( month, name);
An instance of <fixnum>
An instance of <string>
short-weekday-name maps weekday symbols,
as returned by date->weekday,
to their short (3-character) English name.
short-month-name does the same for month numbers (1-12)
and month names.