TimedState.cs

public class TimedState
{

    SeriealizedState data;
    ITimed timed;
    public ITimed Target { get { return timed; } }
    public SeriealizedState Data { get { return data; } }

    public TimedState(ITimed timedObject, SeriealizedState serialized)
    {
        timed = timedObject;
        data = serialized;
    }
}

public abstract class SeriealizedState
{

}