Millennium bug

A perceived problem with computers around 31 December 1999, relating to the way in which they store dates.

The problem was that years were stored in some systems as two digits - for example '99' - rather than as four digits ('1999' in this case).

The concern was that date-dependent computer systems might fail around 1 January 2000, if they mis-coded or mis-interpreted the date.

Some concerned individuals and businesses withdrew their funds from banks around this period.

Also known as the 'Y2K bug'.

See also

• Millennials
• Y2K