Y2K problem

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Y2K problem


Y2K bug:

see Year 2000 problemYear 2000 problem,
 Y2K problem,
or millennium bug,
in computer science, a design flaw in the hardware or software of a computer that caused erroneous results when working with dates beyond Dec. 31, 1999.
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Y2K problem

(Year 2000 problem) The inability of older hardware and software to recognize the date after the year 2000. The reason they could not was because the year was stored with only two digits in many databases; for example, 12-11-03 instead of 12-11-1903. Therefore, after the turn of the century, was this date 1903 or 2003? Every program that dealt with dates could have problems.

Dates Are Critical
Financial transactions often match dates in database records with today's date or with a future date. If the system does not handle dates correctly, bills do not get paid, notices do not get triggered and actions are not taken. After 2000, any system that could not recognize the change would cause erroneous output with applications that dealt with future dates. Although warnings of disaster prevailed, there were only a few incidents when all was said and done.

Fixing It Was a Massive Job
The solution to this "millennium bug" required upgrading hardware to support four-digit years, converting files and databases to four-digit years and converting all the software that referenced dates. Enterprises had a huge amount of legacy data files and thousands of programs that accessed them. With many older applications, the programmers who wrote them were long gone, and documentation was lacking. In many instances, the source code was missing. Even when changes could be made, the time it took to test them was taxing on the IT staff.

Just to Save Two Bytes!

The problem originated with punch cards that go back to the early 1900s. In order to cram an entire order or customer record into a single punch card with 80 or 90 character columns, the year was shortened to two digits. Why waste two columns for "19" when it was going to be "19" for a very long time. When punch card systems were converted to magnetic tape in the 1960s, and there was ample room to convert to four digits, laziness prevailed because 2000 still seemed very distant. Saving two columns (two bytes) in a punch card was appropriate, but not when there was ample storage on tape.

Problems Occurred Even Before 2000
For example, imagine a company wanting to delete customers who had not purchased anything in the previous five years. The program logic would add 5 to the year of the last order and compare the result with the current year. Suppose a customer last ordered in 1995 and the current year were 1996. Add 5 to 95 in a non-Y2K compliant system and the result was 00, not 2000. Since 96 was greater than 00, the customer record would be deleted. See data aging and Year 2038 problem.

The Y2K Problem
When data were copied from punch cards to magnetic tape records starting in the 1960s, the two-digit year was generally copied verbatim because the next century seemed very distant. See 3 C's.

About Time
This conference was from the Software Productivity Group, an organization that provided the necessary training to deal with this sticky subject. (Image courtesy of Software Productivity Group)

Making a Strong Point
Year 2000 compliance software from Isogon was used to test IBM mainframe applications running the MVS operating system. (Image courtesy of Isogon Corporation.)

Perhaps Overly Dramatic
There was a lot of concern before the millennium that things could get out of hand. However, had the world not spent hundreds of billions of dollars revamping thousands of applications, there would have been many problems. There were only a few.

Even Before Y2K
Program maintenance is always a problem in this industry. This commentary from PROCASE Corporation was created more than a decade before Y2K. PROCASE provided software that could flow chart a program from its source code in order to make it understandable.
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References in periodicals archive ?
Practically all large organizations are addressing the Y2K problem in some way, despite the lack of preparation in most small ones; the public sector generally lags behind the private sector.
Make sure that you don't ignore internally generated written memoranda regarding Y2K problems and the steps you are taking to address them.
We have recently heard from the president's Y2K Council and the Federal Emergency Management Agency that we can model our preparations for Y2K problems on preparing for a typical winter storm.
Some smaller servicers are particularly vulnerable, as they tend to lack the comprehensive resources available to larger operations to dedicate to the Y2K problem. Mitigating the advantage of more resources is the inherent complexity that comes with greater portfolio size: Any data discrepancy - even a small one - will have a necessarily magnified effect on a larger portfolio.
Every sector of the communications industry - broadcast, cable, radio, satellite, wireline and wireless telephony - could be affected by the Y2K problem. All sectors of the global economy, including financial markets, depend upon reliable telecommunications.
Authors Peter de Jager and Richard Bergeon are two of the most widely recognized experts on the Y2K problem. They write in a clear, easy-to-read style and give a realist's - as opposed to an alarmist's - view of the situation.
The majority of government officials and large corporations have been optimistic about Y2K, but they also make no assurances that there will be no serious Y2K problems or disruptions.
* A mere two percent of respondents expect to lose their job as a result of a Y2K problem.
Fortunately, most landlords have already taken these precautionary steps to avoid the potential litigation and liability which could result from Y2K problems.
Keyes as saying, "We started out several months ago thinking about the Y2K problem. We've gone from that to realizing this may be the single biggest opportunity we've ever had.
Some experts believe Y6B poses far more danger to far more people than the so-called Y2K problem, which may cause massive computer malfunctions in the year 2000.
Consider the task facing a medium-sized chemical company, which typically has 8,000 computer programs with 12 million lines of code, according to Dennis Grabow, who has written on the Y2K problem for Chemical Engineering magazine.