PC version by Dave Katz,
by John Mackin,
by John Walker,
This program is a clock that shows which portion of the Earth's surface is
illuminated by the Sun. It displays the current time in both the local
time zone and UTC.
To set your time zone correctly, put the following in AUTOEXEC.BAT:
The "5" is the number of hours west of UTC for the local time zone,
and "EST" and "EDT" are the strings to display for standard and daylight
time, respectively. Alter for your own time zone as need be. If you
don't set it, it will default to the Source of BSD Unix (PST8PDT).
This program is public domain and may be freely copied as long as the
notices at the top of sunclock.c remain intact.