Many organizations require that a consistent date format be used throughout their environments.
Unfortunately, this is not necessarily the same format from organization to organization. The two-digit shortcuts, as well as the custom date formatting features of most common products, are designed to accommodate those needs. Within Microsoft applications for instance, the two-digit date logic is applied to meet that application's particular needs. For example, when you use Microsoft Outlook for scheduling, the date window is different than the date window for birth-dates in the contact manager. The reason for this is that those two functions require different logic to better serve the user's needs.