Aye, I guess I meant very very "approximate" not "exact" ;)
So what we need is a fixed observer point for all Time Travel operations. Given we already use Greenwich for our Earth based coordinate and time systems, I propose we erect a huge needle in the middle of Greenwich. This needle (the "Time Needle" perhaps) will be our (0,0,0,2012-10-02) reference point.

We'll have it pointing as straight up as possible and that can be the y axis. ;)

Ah well, regardless of the shape of our universe, our galaxy will have moved slightly from the "emission point of all matter created during the big bang" ;)
If we can observe other galaxies moving away and towards us, it's logical to assume they're coming from 'somewhere'.

Inputting a figure of 10,000 years into your time machine is pointless. You'd have to be *very* *very* accurate with your jump times to end up in exactly the same physical spot you were when you set off.
In 10,000 years, not only will the orbit of the Earth have expanded out slightly around the sun, but the position of the sun relative to the gravitational centre of our galaxy will have changed also. Likewise, our galaxy will have moved out slightly from the centre of the big-bang too.

Chances are with all these options you'll end up floating dead in space.