Year 2000 problem — class of computer bugs related to dates beginning in the year 2000
The Y2K bug prompted a global remediation effort costing hundreds of billions of dollars to prevent calendar-date errors from disrupting critical computer systems at the turn of the millennium.
Key Facts
- Estimated remediation cost
- $400 billion to $600 billion
- Root cause
- Two-digit year storage making 2000 indistinguishable from 1900
- Major errors reported
- Few
- U.S. response leader
- President Bill Clinton
- Date of concern
- January 1, 2000
By the Numbers
Cause → Event → Consequence
Many computer programs stored calendar years using only two digits, representing, for example, 1985 as '85'. This meant the year 2000 would be interpreted identically to 1900, creating the potential for widespread date-calculation errors across computer-reliant industries and global infrastructure.
As the year 2000 approached, governments, corporations, and IT professionals undertook an extensive worldwide effort to identify and correct date-handling code across countless systems. Public alarm grew, with some individuals stockpiling supplies and withdrawing savings in anticipation of infrastructure collapse on January 1, 2000.
Contrary to fears, few significant errors materialized on or after January 1, 2000. Supporters attributed this to preemptive remediation, while critics noted that even poorly prepared countries experienced minimal disruption. President Clinton described Y2K as 'the first challenge of the 21st century successfully met.'