Y2K

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Y2K

• Justin Kovacich

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What was the y2k bug?

• Dates expressed as 2 digits instead of 4.
• Made date comparisons
• between the 1900s
• and 2000s incorrect
• 99 gt 00, 1999 lt 2000

http//courses.cs.vt.edu/cs3604/lib/Y2K/class.htm
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What caused it?

• In the early days of programming, space was a
  precious commodity
• No need to waste 2 digits, just append a 19 to
  the front, or add 1900 when displaying to the
  screen.

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No one saw this coming?

• Use of 2 digit years was a common practice in
  art, but it is typically easy in paintings to
  distinguish centuries.
• Bob Berner first reported the issue in computing
  in 1958
• The problems with 2 digit years were reported in
  journals from the 1970s on, who worries 30 years
  ahead of time about such things?

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Government Response

• Senate hearings about y2k began in 1996
• Senate estimates for the cost of U.S. spending on
  fixing y2k issues 300 billion
• Estimated cost for the Federal Government 30
  billion

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The Fears

• Power grids shut down
• Our electronics cease
• to function
• Spreadsheets show
• incorrect dates

http//img.zdnet.com
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The ball drops and

• Power stayed on
• as millions across
• America watched
• Peter Jennings
• and Dick Clark
• celebrate the
• transition and
• survive the apocalypse

http//www.smbc-comics.com
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Costs

• Global y2k costs estimated at 600,000,000,000
• ATT spent 500 million, Citigroup 650
  million.

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Lets compare strategies

• Nations like Italy and Korea spent relatively
  little on prevention, with the fix on failure
  mentality.

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Were the costs justified?

• Ask any of the COBOL consultants (who in some
  cases wrote the bug and then decades later the
  solution), and the answer is yes. The software
  and hardware didnt fail because the corrective
  job was done well.
• Backup systems in place due to the possible y2k
  glitches kept NYC running after 9/11 in NY.

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Real Life Horror Stories.

• A Japanese nuclear power plants alarm sounded 2
  minutes after midnight
• Japanese cell phone text messages began erasing
  older messages.
• 150 slot machines stopped working in Delaware.
• 103 year old woman invited to join a local
  preschool.

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Y2k Lessons learned

• Hardware and software should be, within reason,
  written to be flexible and extendable.
• Proper documentation likely couldve saved some
  of the billions spent on last minute prevention

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A Unique Problem

• A globally finite and definite deadline for
  software compliance.
• Worldwide effort to ensure software and hardware
  was set up correctly.

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Other time bugs

• 9/9/99 was sometimes assigned as an end date
  marker, which potentially led to problems on
  September 19th, 1999.
• Y10k, if we can make it that long.
• Year 32768 signed 16 bit ints
• Year 292,277,026,596 When unix time will reset
  to 0.

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The end!
www.pbase.com/richo/fireworks
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References

• Y2K Lessons Learned 2000 Braithwaite,
  Timothy
• Year 2000 Best Practices for Y2K Millennium
  Computing 1998 - Lefkon, Dick.
• http//americanradioworks.publicradio.org/features
  /y2k/index.html - Chris Farrell, accessed
  2/19/2008

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Homework

• Why was only having 2 digits for year comparisons
  suddenly a big deal in the late 1990s?