CS294-8: Principles of Fault Tolerant Computing
Fall 2000
Homework 1: Anatomy of Failure
Hakim Weatherspoon hweather@cs.berkeley.edu

Y2K: The "Millennium Bug" System Failures

Y2K Problem

The Year 2000 Problem (Y2K) exists in computer systems where a two-digit year field is used and the years 2000 and after cannot be distinguished from years before (i.e. 2000 from 1900), resulting in potential erroneous date-based calculations.

In January, a World Bank report estimated that only 21 of 139 developing countries had taken concrete steps to address the year 2000 problem. The report went on to anticipate year 2000 impacts on power, telecommunications, energy, food distribution and medical care in developing countries.


The millennium bug caused 67 "significant" computer failures across the world in the first week of the New Year. The bug count was collated by the Year 2000 Research Center, which was set up by accountants KPMG and the British Bankers Association. The glitches ranged from failures reported at US power stations to problems with Internet music systems around the world.

As of March 1, 2000, There were no significant leap year computer problems reported according to the International Y2K Cooperation Center.


The effects from the Millennium Bug could have been catastrophic. However, due to the cooperation of the worlds governments and hundreds of billions of dollars spent to kill off the bug worldwide, Y2K ended as mere only glitches.

Related Sites

- CNN - The Hunt for Global Glitches.
- Sightings - The Millennium Bug.
- Y2K Around the world - facts and figures from the UK and around the globe on possible effects of the Y2K bug. From the BBC.
- Y2K Experiences - survey of IT professionals to determine what kind of Y2K glitches may have been encountered. Conducted by TechWeb/CMP Media.
- President's Council on Year 2000 Conversion - main U.S. government web site, with links to other U.S. agencies.
- International Y2K Cooperation Center - includes links to the government Y2K pages of dozens of nations.
- Keynote Y2K Internet Performance Millennium Watch - monitoring the effects of Y2K on the performance and availability of the Internet, using web sites that are physically located in each of the world's time zones in which there's a major business center.
- The Internet Stands Up
- Year 2000 Crisis Editorial Cartoons - from newspapers around the US, updated daily.

U.S. Government Web Sites

- President's Council on Year 2000 Conversion - main U.S. government web site, with links to other U.S. agencies.
- Federal Reserve Board Y2K Page - includes operational status for Federal Reserve customers.
- FTC: Year 2000 Consumer Information - aims to provide the consumer, with reliable, helpful information available from both government and non-government sources.
- FEMA Y2K Issues - the Federal Emergency Management Agency.

Hakim Weatherspoon hweather@cs.berkeley.edu