The Data Horizon is a tool, used to define (limit) the time span for the marked data used for backtestesting.

Each Data Source has its own Data Horizon settings. Here is where you choose which Data Source you want to change.

1. Maximum data bars – this value can vary between 300 and 50 000. This setting does not change the data files. The program will load the file’s data and filter the bars using the settings below.
2. Start Date – you can change this option to select date where the backtesting data should start. There must be a minimum of 300 bars between the Start and the End Date. If you chose a Start Date that is “too close” to the End Date. The Start Date will be automatically set far enough in the past, to make sure there are 300 bars present.
3. End Date – the limit at the end of the period you selected;

FSB Pro can use data from shorter periods data files. This setting tells FSB Pro how many shorter period bars it may load. See more about that in Intrabar Statistics

If the Generator or the Optimizer is working with this data, they will not reload the data upon changing the settings. This happens because the Generator and the Optimizer copy the data for their own use when they start working. However if you are editing a strategy, for example, and click Reload Corresponding Files this will reload the data for the backtest.