Updated: A colleague in Frankfurt has thoughtfully provided a German version of this customisation. I've merged it with the English version and packaged it into a custom component for convenience. It's available from the Partner download area. I've left the original instructions and page for use with other languages, but if you're adding this for an English or German install all you need to do is run the component.

We're asked fairly regularly for an easier method of adding forecasting quarters. I believe this may be somewhere in the works, but in the interim here's something to tide you over.

The following adds a new screen to the Data Management area of CRM. Its only purpose is to allow you to add new forecasting quarters.

The method of storing forecasting quarters was changed in a fairly recent version, so this page will only work for v7.0 and higher.

This was written to work for English versions of CRM (UK and US), but could be modified easily to accommodate other languages. I've marked areas that would need to be changed with a ***TRANSLATIONS*** tag.
First of all, save the file attached to this post to your ..\CRM\WWWRoot\CustomPages directory. Remove the .txt extension, so that it's named incForecasts.asp. You may need to set permissions so that it's accessible to your anonymous user.

Next, go to Administration -> Advanced Customisation -> System Menus -> AdminDataManagement.

Add a new item using the following settings:

Caption: Forecast Periods
Action: customfile
Custom File: incForecasts.asp
Bitmap: forecast.gif
You’ll now have a Forecast Periods option under Administration -> Data Management. Just click the button to add more forecast quarters.

Once you've added your forecast quarters, you'll want to refresh your metadata. It won't break anything if you don't refresh immediately, it's just that the new quarters won't be available from the menu