Year 2000

Also found in: Acronyms.

Year 2000

(Y2K, or "millennium bug") A common name for all the difficulties the turn of the century, or dates in general, bring to computer users.

Back in the 1970s and 1980s, the turn of the century looked so remote and memory/disk was so expensive that most programs stored only the last two digits of the year. These produce surprising results when dealing with dates after 1999. They may believe that 1 January 2000 is before 31 December 1999 (00<99), they may miscalculate the day of week, etc. Some programs used the year 99 as a special marker; there are rumours that some car insurance policies were cancelled because a year of 99 was used to mark deleted records.

Complete testing of date-dependent code is virtually impossible, especially where the system under test relies on other systems such as customers' or suppliers' computers. Despite this, the predicted "millennium meltdown" never occurred. Various fixes and work-arounds were successfully applied, e.g. time shifting.

And yes, the year 2000 was a leap year (multiples of 100 aren't leap years unless they're also multiples of 400).

References in periodicals archive ?
Unfortunately, fixing the Year 2000 problem will not be easy.
As a result, there was no sense of urgency; the year 2000 seemed a long way off.
The report warned that the problem was too complex for companies to guarantee to have achieved complete year 2000 compliance.
PC users can try a simple test that will tell them if their system is year 2000 compliant.
As a result, the consumption of solution SBR is expected to increase from 113 kt in 1995 to 172 kt by the year 2000 (8.
While these accomplishments are indicative of our significant progress in addressing the Year 2000 issue, much work remains.
While Year 2000 remediation efforts may give a temporary boost to economic activity in some sectors, the net effect probably is negative.
The scope of the Federal Reserve's Year 2000 activities includes all of these processing environments and the supporting telecommunications network.