Y2K problem

[neoteric]

I know about the Y2K problem vaguely. I'd like to know why Y2K problem could have been serious if we could not solve it. Thanks.

[lisaj]

Years ago, computer systems, and in particular memory for those systems, was prohibitively expensive. Computer programmers were therefore trying to trim down their software so that it used as little memory as possible, and one of these approaches was to use 2 digit years rather than 4 digits. Software designed and built in the 70s simply wasn't expected to still be running 30 years later, however, the cost of redeveloping legacy systems today is also very expensive, not to mention difficult. This is why software running on the most mission-critical and safety-critical systems such as NASA's Space shuttle, Aircraft, Air Traffic Control and Missile control systems still tends to be very old. It works, and so there's no reason to 'fix' it with a newer version. Of course, the Y2K bug would have meant these sytems could not correctly identify time differences, and this could have caused havoc with correct navigation, timing slots, etc. Of course, most of these sytems could be turned off, so the vision of aircraft falling out of the sky was a little 'doomsday', but still... it made a nice pocket of money for a nervous IT industry.

[Pinotage]

The simple answer is that dates were stored with the year as 2 digist (for the reasons stated by lisaj)

 

When sorting on dates - or doing date arithmetic - the date was treated just like a number - thus its easy to take a date of birth from the current date and work out the age. If today is 22/08/98 and someones date of birth is 01/04/67 then 98 - 67 gives and answer, but when 2000 came the sum 00-67 doesn't work

 

Every major company needed to adjust their computing systems, otherwise bank accounts,, pensions and everything else would have had some sort of failures.

 

above is somewhat simplified, but not much. basically anything that used dates would have had a problem.