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This Month in Business History

The Year 2000 : Y2K

Posada, José Guadalupe, artist. El fin del mundo es ya cierto todos serán calaveras; adiós todos los vivientes, ahora sí fue de deveras 1899. Library of Congress Prints and Photographs Division.

As the world approached the year 2000, there were concerns over how our computers, computer programs/software, integrated systems, etc. would react to the date change from December 31, 1999, to January 1, 2000. As the millennium approached, many wondered if the world's businesses and financial systems would crash. Would airplanes still be able to fly or could there be nuclear accidents? Would these systems be fixed in time to avoid catastrophe?

How did this happen?

In the early days of computing the cost for memory was very expensive. The cost per megabyte of memory in 1970 was more than $3,000,000.1 In an effort to save money on memory, computer programs were written using a two digit year, assuming the "19" for the century. Storing a date in the format MMDDYY (6 bytes) rather than MMDDYYYY (8 bytes) produced a savings of 2 bytes per date stored. This may not sound like much, but consider the needs of a human resources department. The following dates are a short list (not inclusive by any means): hire date; termination date; date of last review; date of last increase; date of birth; rehire date. By only using a two digit year, there was a savings of 12 bytes of memory on these 6 dates alone.

The thought that the programs from the 1960s and 1970s would exist into the year 2000 was not conceivable at the time. Surely the programs would be replaced long before the year 2000. The problem was then compounded further when newer programs were added that needed to access existing data, thus propagating the two digit year.2 Additionally, dates were not only stored in programs, they were also in printed reports and computer screens. Personal Computers (PCs) and microchips embedded in systems all had dates and many, if not all, of them needed to be fixed!

Was this really a problem?

Many were skeptical that a real issue existed. There were early indications, well before January 1, 2000, that there would be problems. Some store computers and ATMs would not accept credit/debit cards because the expiration date on them was 003 and retailer card machines refused to process credit and debit card transactions.4 While these were minor issues, it did highlight that there could be problems on a larger scale.

What was done?

There was a lot of time and money spent in efforts to replace old systems or to correct existing programs. Contingency plans were created and system back ups were planned, just in case. Governments and companies around the world worked to correct or replace their programs in an effort to prevent the projected "catastrophe." Consultants and COBOL programmers were in high demand. In the United States, Congressional committees were established to deal with the year 2000 technology problem and the Year 2000 Information and Readiness Disclosure Act was passed on January 27, 1998 in an effort to promote free disclosure and exchange of information related to year 2000 readiness.5

Early estimates to fix all systems on a global scale ranged from $600 billion up to $1 trillion or more. Federal spending was estimated to reach $7.5 billion and corporate spending estimates came in at $121.96 billion.6 Final estimates globally did not appear to be as high as expected, a report estimated the final numbers at $320 billion worldwide and $134 billion in the U.S.7

End of the world?

Did the world as we know it come to an end? Obviously not, we're still here! While there were "glitches" reported, most seemed to be minor or have a manual work around. Japan had two incidents at nuclear power plants, Australia had issues with bus ticket validation machines, some slot machines in the US stopped working,8 and Microsoft's display glitch with Hotmail9 were among some of the problems reported.

If you have any further questions, please Ask A Librarian.

Print Resources

Many books were written on the subject of the Y2K problem. Below is a sample list of them, but you can find more by searching the library's catalog as described further down. The following titles link to fuller bibliographic information in the Library of Congress Online Catalog. Links to additional online content are included when available.

Internet Resources

These are online resources that discuss the Y2K problem. Many are not around anymore but have been archived in the Internet Archive.


A search for articles in the following business databases using "Y2K" related terms will produce results. Some search suggestions:

  • Y2K
  • Year 2000 transition
  • Y2K computer bug
  • Millennium bug

The subscription resources marked with a padlock are available to researchers on-site at the Library of Congress. If you are unable to visit the Library, you may be able to access these resources through your local public or academic library.

Search the Library's Catalog

Additional works on this topic in the Library of Congress may be identified by searching the Library of Congress Online Catalog under appropriate Library of Congress subject headings. Choose the topics you wish to search from the following list of subject headings to link directly to the Catalog and automatically execute a search for the subject selected. There are many other related subject headings that provide resources covering geographic locations, legal aspects, and more. You may browse the resulting lists or modify the headings with appropriate geographic locations or sub-topics. Please be aware that during periods of heavy use you may encounter delays in accessing the catalog. For assistance in locating other subject headings that may relate to this subject, please consult a reference librarian.


  1. Bourne, Kelly C. Year 2000 Solutions for Dummies. Foster City, CA: IDG Books Worldwide, c1977. p 13. Back to text
  2. Bourne, p 15. Back to text
  3. Bourne, p 23. Back to text
  4. "Millennium bug hits retailers" BBC News, December 29, 1999. External Back to text
  5. Year 2000 Information and Readiness Disclosure Act, Public Law 105-271, U.S. Statutes at Large, 112 (1998): 2386-2395. Available online from GPO Access Back to text
  6. Farwell, Jennifer. "The Big Picture: The True Cost of Y2K." Smart Computing August 1999, Volume 7 Issue 8. Back to text
  7. "Global survey cites good and bad Y2K news," by Network World Staff. CNN.Com. December 29, 1999. External Back to text
  8. "Minor bug problems arise." BBC News, January 1, 2000. External Back to text
  9. "Two glitches hit Microsoft Internet services as New Year rolls over," by Renée Gotcher., January 3, 2000. External Back to text