Date windows vary from one software program to another and even from version to version of the same software program. They are generally not obvious to the user. Many automatically expand YY dates to CCYY dates, assuming centuries in the process. Different programs resident on one PC or in one company may assume different centuries and any number of these may be incorrect. This is not apparent to the user who makes decisions based on incorrect information, perpetuating the problem.
Faulty data needs to be located and corrected.
All data must be assessed for the use of YY years and programs must be assessed for the acceptance of correct data handling. New data must be monitored to ensure that it is year 2000 compliant. Data is continually being exchanged by e-mail, the Internet, EDI, disk, and across networks. Even the common technique of cut and paste may result in year 2000 problems. Data corruption is worse than computer failure as users are often unaware that data has been corrupted and continue to use it and base decisions on it.