What is causing the 2010 bugs?

There are a lot of reports of systems failing to understand the year 2010 but I've no idea why. Current systems I look after are working fine as far as I could tell but I'd like to know what the actual problem is to search better.

Could anyone shed some light on it please?

Edit: http://www.rte.ie/business/2010/0105/bug.html开发者_JAVA技巧 - Information about it affecting credit cards in Germany

Several protocols used in banking and telecommunications - including the SMS protocol - encode the year as BCD in a single byte.

From 2000-2009 one could easily make the mistake of interpreting the year as a standard binary number since the encoding would be the same:

Encoding  Binary-interpreted  BCD-interpreted
0x01      2001                2001
0x02      2002                2002
...
0x09      2009                2009
0x10      2016                2010
...

That is most probably the cause of the Windows Mobile bug.

One possible explanation is in the article below

http://www.theregister.co.uk/2010/01/05/symantec_y2k10_bug/

Reminds me of your recent article about cheap and dirty Y2K bug fixes where some unscrupulous programmers put in a simple if <10 = 20xx otherwise the date is 19xx

SpamAssassin had a rule to mark dates too far in the future as spam:

/20[1-9][0-9]/

The fix came a few days too late, but it's quite simple:

/20[2-9][0-9]/

See you again in ten years.

I've got a system at work that uses a one digit year field. Yes. One digit. So the reason this system is failing is that "2000" is expressed the same as "2010".

The one I heard about was quick fixes people did for Y2K without thinking it through. So if xx < 10 then 20xx else 19xx.

It might be due to the young developers who started their careers after Y2K and are using 1 digit to represent the year.

I took care of a little 2010 fail in a site last weekend, it was just the result of an oversight in coding though.

Someone thought it would be a good idea to set the value of a list item to the current dateTime.year.Now() when the list only contained items up to 2009.

ddlItem.findByText(DateTime.Now.Year.ToString())

Here is a screen shot of the norton symantec endpoint protection

alt text http://img695.imageshack.us/img695/4500/152010112800am.jpg

Really nice that no one @ symantec informed their customers... Till the article was posted: http://www.theregister.co.uk/2010/01/05/symantec_y2k10_bug/

It is that there is a bug in a component that splits the year in two parts. The second part is used in a comparison so that the digit 10 is not in base 10, it's in base 16 meaning that it's 0x10 = 16 (hex).

I used Google Code Search to find y2010 bugs in open source software. I looked for one particular pattern that would indicate a bug (use of "200%d" as a printf format string), and found several projects with that bug. Creative application of search patterns could probably turn up more different kinds of bugs.