Time seems to be so fundamental to the calculations that we make, that it seems to be at the core of everything we do.

Indeed, this is not just philosophically true, time is very often the x axis, by convention, and we consider its distance from 0, in respect to some variable y, and amongst others if you go into more than 2 dimensions. Furthermore, whilst time isn't always explicitly the x axis, I always find that time is a composite of either variables x or y, but never x and y.

Is this possible though? Can time be part of both variables x and y, or is it always confined to one variable alone? Furthermore, what if you are working with say, 5 dimensions (which I have never ever done, for the record), could time form the basis of 2 variables plotted against the other 3? 

As a side note, the driving force for this question is not to see whether more (or less) can be achieved by doing this, (if it's even possible), I just find this to be mathematically and scientifically fascinating, as it seems to be a feature of the underlying fabric of maths and science.