Ok,
Here is the big secret to the xa. Nighttime landscapes. Yup they dont work with this camera, since almost any nighttime scene has some street lights that fool the light sensor and expose wrong.

You can make a cutout from cardboard or something dark, shape it to the light sensor on the face and use a rubber band or something to hold it in place. Then probably set the film speed to the slowest like 25. Set your aperture to f8 or whatever for the scene and you will basically trick the camera into the longest shutter speed it has. Since you can set the aperture manually, you can get a nice sharp picture and expose the night properly.

This is neat because the camera is tiny and you can carry a tiny tripod and still get great night shots on vacation. This trick works on almost all auto cameras actually, it is just that the xa is a great camera for this.

How long is the longest exposure time?

The manual says 10 seconds, but I think it will go even longer.

I don't recall exactly, but I believe it is substantially longer. And I'm not sure I agree about the original post, as I have made XA shots at night with a campfire in the scene on chrome film, and everything worked well. It is likely (this was many, many years ago!) that I used the backlight compensation switch which was sufficient to compensate for the brightness of the campfire.

Earl

I have also used either the backlight compensation or the fiddling with the ASA (so I could use the the self-timer) to help extend the exposure time on my XA. But I do think the idea in the original post would work as well.

the exposure time on the XA is 16 seconds.

this is one of the reasons why it's liked more than minox by the night photographers :)