Problems will occur even before the year 2000

All one-year calculation will start to fail in Jan 1999, not Dec 1999.

Your insurance policy will say the expiration date is Jan. X, 1900. Your information system will recognize that the 1-year bond you issued was payable in the year 1900.

Therefore, all re-coding and testing should be done before the end of 1998 to make sure that the correct year-end data will be carried forward to the year 2000. Companies also need extra time to debug the still-unfixed codes by Dec 1998. Most one-year calculations will fail from the first day of Jan 1999, not Dec 1999.

All businesses and organizations should test all the programs in operation beforehand, and the programs that will continue to be used after the year 2000 should be tested and examined thoroughly.

Things will fail that no one has ever thought of.