The following procedure can be used to get a good sun clock or
day/night map in Guide. It does not automatically update, however.

PREPARATION

Create a display centered on the Sun with the following
characteristics:

Display Level 9 (half-degree field)
Limiting magnitude 16 (to get all GSC stars)
Display uninverted, with ecliptic north up
Display grid set to ecliptic grid, with an RA interval of 2 seconds,
and an arbitrary Declination interval; I used 10 degrees.
Display should have a central cross hair.
Sun displayed with a line figure (this might require changing and
changing back to set up).

This will be very strange in appearance, but it's only the means to
the end. Mine has the Sun's magenta outline superimposed on a grid of
vertical lines about 3 mm apart. It has dozens of faint stars shining
through the Sun in a dark sky.

** Save this display setup as a mark (I called mine Sun Clock).

ACTIVATION

1. Load the Sun Clock mark.
2. If needed, set the time in the time menu.
3. Center the display on the Sun (ctrl-0 (zero) shortcut).
4. Find the star closest to the Sun's ecliptic longitude. This is
where the grid lines should help. Look between the grid lines flanking
the central cross for your best candidates.
5. Right click the star. You will get the brief info box indicating
you have clicked on the Sun. Click Next. Your star should have a
cursor on it now.
6. Click OK.
7. Use the Extras menu to show eclipse.

This will provide a day/night map for the time of conjunction. This
may be different from the set time by some minutes, but probably not
enough to make a noticeable difference in the map. (On a 1024 x 768
display, one pixel corresponds to 1.4 minutes in the terminator near
the equator.) The local time of conjunction can be found by right
clicking the map at your location. The 2 second grid corresponds to
about 12 minutes of solar motion. More stars, such as in the GSC 2,
USNO A or B catalogues, might help.

This procedure may depend on some parameters that I've taken for
granted, so post any problems. There does seem to be a conflict
between the ecliptic grid for the sky display and the earth map. My
map's lat-lon grid vanished.

The basic idea behind this procedure is that Guide's eclipse and
occultation capability has always shown the day/night areas of the
earth to allow observers to access their viewing prospects. It just
needs to be activated for an arbitrary time. The easiest way to
arrange a conjunction for a particular time and that changes little
with geographic location is to select a large object fairly far away.
The moon is too close, while other solar system bodies are too small.

Ross Shuart