I've been trying to think of ways to play with the ideas of multiple time dimensions. "It's weird", as you might guess.

But I thought of a "setup" where you can have an arbitrary number of time dimensions and/but it still is easily visualizable for us (apparently) 4D beings.

Instead of one time dimension t, what if we had a time dimension T that was composed of other time values t0, t1. We could call it a "time vector". T = <t0, t1>

Define a "system" in this universe (S) to be "a collection of matter that has a certain arrangement S(T) for any value of T.

Terms like "matter" and "arrangements" are chosen for their vagueness!

The various components of S could be affected in different ways and to different degrees by the "scalers" t0 and t1.

A very contrived example: An atom (the usual kind) has its x, y, z determined by its 3-velocity, as t0 increases (like the usual t).

But the rate at which it decays into another atom(s) is a function of t1. So, plutonium moves faster along the t1 axis than does helium.

Not great. Requires a lot of belief-suspension.

Maybe more examples go: here

Note that t0, t1 describe a plane, and the path of S takes through that plane are the series of values of T. It just happens that T is composed of more than one "scaler" time dimension.

This is probably just a bunch of hockey, but it does give us a way to play in games, pretending there are "multiple time dimensions".

Q: t is in a sense dependent on the concept of "space". Can we work that out for a system that uses T also? Maybe a game that uses this idea would have to have a kind of Relativity and "speed of light" built in on order to make (more) sense.