Choosing the optimization Time Frame in MT4 Optimizer

Trading Systems Expert Advisors and Automated Trading
1

I’m trying to optimize a simple AI strategy, i can’t post a link because this is my first post.

Somethign like

double perceptron()
  {
   double w1 = x1 - 100.0;
   double w2 = x2 - 100.0;
   double w3 = x3 - 100.0;
   double w4 = x4 - 100.0;
   double a1 = iAC(Symbol(), 0, 0);
   double a2 = iAC(Symbol(), 0, MovingAverage1);
   double a3 = iAC(Symbol(), 0, MovingAverage2);
   double a4 = iAC(Symbol(), 0, MovingAverage3);
   return (w1 * a1 + w2 * a2 + w3 * a3 + w4 * a4);
  }

I’m using the optimizer to choose the best values for parameters and stop loss…of course the values change depending on the time frame i choose for the optimizer.

In this case in particular, and more in general, is it always better to use more data for the optimizer?
I have data up till 1999. Or is it better to train it on the current month and re run the optimizier every 2-3 days and change the values accordingly??