[ElkGroveDan]

A "Sol" would be the length of a day on the Sun. You know, from midnight-to-midnight at the same spot on the surface of the Sun. Go ahead, try it yourself, don't take my word for it -- but make sure you go there at night, OK? It gets really hot in the daytime.

I agree with you on the goofy terminology, but since you brought it up: How do you know when it's night on the Sun? When the Galactic core sets?

[Don Joe]

How do you know when it's night on the Sun?

Same way you know it's night anywhere else, of course. It gets dark!