What's always amazed me is that the moon is often associated with the night when it appears in the day very often as well. It's harder to spot it during the day of course, but there she is (moon is feminine in my native language, left the mistake, I like it like that).

So, I'm not an expert but it seems moon / sun is equivalent to a night/day opposition. But to be honest I'm having a hard time thinking of the moon as anything other than the object that reflects the sun's lights and causes tides. But I wouldn't oppose the moon to the sun anyway, if only because the moon is a damn precious source of light at night when there is no public lights.

And you're welcome, I do enjoy venting about my little sister whenever I get the chance :)