Hi Bernd,

> I'm doing mostly cometary work. So when I plot a trail I use the time I
> want to image the comet with CCD. For many comets I start at the end
> of nautical twilight in the evening and I want to finish at the bginning

of

> nautical twilight in the morning. So I set the time accordingly and don't
> have it set automatically to a full hour or midnight.

You right, that makes sense.

> By the way: which midnight? Local, UT or the middle between end and
> beginning of twilight?

I prefer UT.
I have set the time of GUIDE at UT and I'm using at GUIDE.DAT the line
TOFFSET to make the correction between GUIDE and the cpu time, which runs at
local time. The option "full hour/day" should use the time setting of GUIDE.
A user, who runs GUIDE at local time would get the marks in local time too -
just a suggestion.

I wish you many clear nights at your observing session!!

Oliver