Time travel issues

I'm intrigued by the possibility of time travel, though I don't obsess on it (in other words, I probably haven't read all the books you have on the subject). However, it occurred to me the other day that most fictional accounts seem to either overlook or oversimplify one problem. If you are going to travel in time, you probably won't be traveling in space simultaneously (though some use space travel as the means by which time travel occurs). In "practice", as fictionalized, this becomes an issue of making sure that you don't place yourself inside a wall in the future, or possibly a glacier in the past.

That acknowledgment of the problem leads to yet another error that would be made by a non-physicist. They (the author/screenwriter/whatever) are assuming that your space displacement is zero ... but relative to what? The earth is both spinning and moving rapidly through space as it orbits the sun. If you move in time but not in space, you would find yourself in outer space, unless you timed your travel precisely so that you caught earth on another orbital path.

But that assumes that the sun about which we revolve is stationary, which it is not.

Oh well, 12 Monkeys is still a pretty good movie. And ST:TNG still sucks eggs.