Year 2000 problem

An electronic sign at École centrale de Nantes on 3 January 2000, incorrectly displaying the year as 1900. Translation: "Welcome to the Central School of Nantes 12:09 3 January 1900."

The term Year 2000 problem, or simply Y2K, refers to potential computer errors related to the formatting and storage of calendar data for dates in and after the year 2000. Many programs represented four-digit years with only the final two digits, e.g. 1985 as 85, making the year 2000 indistinguishable from 1900. Computer systems' inability to distinguish dates correctly had the potential to bring down worldwide infrastructures for computer-reliant industries.