The major common feature of these problems is their inability to deal with dates beyond December 31, 1999. There are two types of products that are likely to contain Y2K problems, software and embedded systems. Probably the most common shortcoming of software products in dealing with the year two thousand is that they store year data in two digit form. This can cause a problem when performing time calculations that involve two years from different centuries. Some systems even use the year 99 or 00 as a special marker and not as a year.
Embedded systems have similar problems to software systems.
Generally in the case of embedded systems there is limited storage space for date and time information so at some point in time the largest storable value will be exceeded causing potentially catastrophic failure of the product. Year 2000 compliance shall mean that neither performance nor functionality is affected by dates prior to, during, and after the year 2000. Compliance Rules 1. No value for current data will cause any interruption in operation. Date based functionality must be consistent for dates prior to, during, and after year 2000 .