How would I go about implementing a stopwatch with different speeds?

Question

Ideally I would like to have something similar to the Stopwatch class but with an extra property called Speed which would determine how quickly the timer changes minutes. I am not quite sure how I would go about implementing this.

Edit

Since people don't quite seem to understand why I want to do this. Consider playing a soccer game, or any sport game. The halfs are measured in minutes, but the time-frame in which the game is played is significantly lower i.e. a 45 minute half is played in about 2.5 minutes.

Answer 1

Subclass it, call through to the superclass methods to do their usual work, but multiply all the return values by Speed as appropriate.

Answer 2

I would use the Stopwatch as it is, then just multiply the result, for example:

var Speed = 1.2; //Time progresses 20% faster in this example
var s = new Stopwatch();
s.Start();
  //do things
s.Stop();
var parallelUniverseMilliseconds = s.ElapsedMilliseconds * Speed;