Drupal Question:

Given that our choice of short name is "onthisdate", start the module by creating a folder in your Drupal installation at the path: sites/all/modules/onthisdate. You may need to create the sites/all/modules directory first. Create a PHP file and save it as onthisdate.module in the directory sites/all/modules/onthisdate. As of Drupal 6.x, sites/all/modules is the preferred place for non-core modules (and sites/all/themes for non-core themes), since this places all site-specific files in the sites directory. This allows you to more easily update the core files and modules without erasing your customizations. Alternatively, if you have a multi-site Drupal installation and this module is for only one specific site, you can put it in sites/your-site-folder/modules.
The module is not operational yet: it hasn't been activated. We'll activate the module later in the tutorial.