Comment 6 for bug 880525

The thing is that the movement can be coarse as it's a step of time day after day.
And not as smooth as it can be if it is for example to watch the moon motion through time.

But there's a trick to fix the sky position instead of the horizon in nightshade by selecting a star (choose a zenithal star for example) and centering the view on it.
That way you'll get the sky still and with the command "timerate" you get planets movements smoothly.

Example selecting Vega:

select HP 91262
flag track_object on
flag atmosphere off
flag landscape off
flag cardinal_points off
flag show_tui_datetime off
timerate rate 86400
wait duration 120
script action end

It works perfectly and that way there's no need to create a new command.

Lionel RUIZ