The Y2K bug (also called the Millennium Bug or Year 2000 problem) was a widespread computer concern in the late 1990s. Many older programs stored years using only two digits, so there were fears that computers would interpret the year 2000 as 1900, causing widespread failures. While the actual impact was minimal thanks to massive remediation efforts, the panic it generated was very real -- and Y2K Joke pokes fun at that hysteria.