Well, I should think that there is at least d(x,y,z) and t(a,b,c) (to pick arbitary variables for time. a would commonly be t, though. X is is forward along the primary direction of a given coordiate system, y is perpendicular to this, and z is perpendicular to both of these. Likewise the three temporal positions.
The difficulty this would cause, though, is in rate of change. Take, say b, and name it T. This would be the left-right movement in the temporal dimensions, and would essentially be a change in what we would call 'dimensions' or timelines. Try deriving d with respect to T! Wouldn't that be wacky? You would have the rate of dimensional shift of a given point. Sounds like something that Belthesar would like...
Actually, come to think of it, our normal time is the same sort of thing, we just do not notice it. We are constantly jumping between temporal 'points'.
However, when dealing with time travel, or any sort of travel, a better way of putting things is spherical coordiates. This would give the orientation and displacement away from the original.