Before starting any testing, set the operating system to display four-digit years. This is important because it makes the date display unambiguous. Otherwise, how can one tell whether a particular date reference like 1/1/00 means 1/1/1900 or 1/1/2000? However, there are potential side effects to this process (see below).
Windows 3.1 users should open the control panel, then the international icon and click the "change" button for date format. Check the century checkbox in the short date format. Ensure the long international format shows four-digit years, too. In Windows 95, from the Start button, choose settings, control panel, regional settings. Then select the date tab, and in the short date style, add two more "y"s to make the year yyyy instead of yy. This will set the default date display for many Windows applications to a four-digit year format and will remove ambiguity.
Be warned that advancing the system date to test applications can cause problems. Some licensed software will expire in the year 2000 and the Telecom Eireann CD-Rom telephone directory, for example, is valid only for one year. Some of this software may refuse to function again when the date is reset to the present.
For this reason, it is important to have a valid backup before beginning testing. Preferably, tests should be carried out with copy data on spare test PCs that can be erased and restored if necessary.
Many application users don't take the problem seriously and take the assurances of the software vendors at face value. It is much more sensible, as Ronald Reagan used to say, to "trust, but verify".
A typical software "warranty" might say: "The [product] and any related documentation is provided `as is' without warranty of any kind, either express or implied, including, without limitation, the implied warranties or merchantability, fitness for a particular purpose, or non-infringement. The entire risk arising out of use or performance of [product] remains with you." To test accounting packages, enter transactions for the dates 1999.12.31, 2000.01.01, 2000.02. 01, 2000.02.29, and 2000.03.01. If the package can accept those dates, try period-end, VAT period-end, and end-of-year processing for both 1999 and 2000. Run reports across all date ranges to check that transactions list in the correct order and that date calculations such as debtor ageing are correct.
A detailed list of issues relating to Microsoft's Access database is provided by FMS (www.fmsinc.com). It describes Access 2 as "non-compliant" because it always interprets two-digit years as 19xx. The default Access 2 input mask only allows the entry of twodigit years, so inputting "00" sets the year to 1900. To correct this, go to design view, click on input mask, and either clear the input mask, or make it 00/00/0000.
Access 95 and later versions interpret a two-digit year differently depending on the version of oleaut32.dll installed on the system. Some versions assume that the century is the current system date century. Others work in the window of dates from 1920 to 2019. Office 97 uses the window 1930-2029.
The fact that software is relatively new does not mean it has no problems. JavaScript, for example, has inconsistent behaviour in its get-year function. It returns a two-digit year before 2000 and a four-digit year after that. Internet Explorer 4 empties the cache - and your e-commerce cookies with it - when the year is less than 70.
To have confidence that systems will still be working a year from today, users need to do their own testing as well as checking manufacturers' compliances statements (see panel). Those who have not yet started don't have much time to spare.
pobeirne@sysmod.ie