If you want to get a glimpse of what was the Y2K Bug craze in 1999 Ullman’s chapter on it is a must.
Millenniums may ask: “What was the Y2K bug?” Well, as one who was actively working in IT at the time, it basically was the number of seriously heavyweight IT-reliant- and IT-provider-based organizations running crapped out, moth-eaten, disaster-ready systems for critical public service and infrastructure functions, systems that were originally developed for Noah's GPSing around Ararat, beggars belief. The problem with the earlier Y2K and other system's potential 1970s-based clock issue and its siblings was and is their potential for cascading. The Y2K bug did, indeed, bite a lot of systems, but it did not go critical and ignite a runaway reaction. However, before the event absolutely no-one on the planet knew for sure whether it would or not.
If you're into Computer Science of the Personal Kind, read on.