Proper noun
Y2K bug
the millennium bug
“Fixing bugs in old legacy systems is a nightmare: it’s spaghetti and nobody who wrote it is still around,” says Paul Lomax, who handled the Y2K bug for Vodafone. Source: Internet
Programmers wanting to avoid the Y2K bug had two broad options: entirely rewrite their code, or adopt a quick fix called “windowing”, which would treat all dates from 00 to 20, as from the 2000s, rather than the 1900s. Source: Internet