Legacy computers and the Space Shuttle:

The U.S. Space Shuttle computers cannot tell one year from another. Some of the software, when it hits December 31st, goes on to December 32nd (or, day 366). This is why the Shuttle can never operate through a change of year. The Shuttle control computers on earth do recognize the changing of the year, but some of the computers on the Shuttle do not, which makes News Years Eve flights impossible. The Shuttle is reaching the end of its useful life, and that three decade old software bug is one of many ways it is showing its age. The Shuttle was designed in the late 1970s, and many of the computers are still using 1980s computer technology. The web, and sites like eBay, have been a salvation for the Shuttle. That's because these auction sites make available a lot of ancient (1980s) computer technology, to provide spares for Shuttle gear that is no longer manufactured.