Year 2000

programming (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).

PPR Corp Y2K FAQ.

(2003-08-15)