April 19, 1999
Cover

DATES WITH DESTINY?

BY WARREN CARAGATA

Jan. 1, 2000, is not the only date that can give computers indigestion. Others are:

* AUG. 22, 1999: Satellites used to provide geographic-positioning data measure time by weeks. On Aug. 22, the system will roll back to zero after hitting the maximum date range of 1,023 weeks. Some computer systems do a time check using the satellites.

* SEPT. 9, 1999: Programmers may have used the code "9999" to indicate the end of a file. Sept. 9 may be written "9,9,99." But few have ever come across such problems. Environment Canada programmer Susan Wild calls this an "urban legend."

* FEB. 28-29, 2000: Next year is the first time in 400 years that the opening year of a century is a leap year. If programmers of original codes forgot that, these dates -- and the fact that Dec. 31, 2000, will be the 366th day of the year -- will cause failures.