

Fighting a 30-year-old software bug - levosmetalo
http://blogs.perl.org/users/ovid/2013/10/fighting-20-year-old-software-bugs.html

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patmcguire
My first thought was, "I remember this. Blame Joel Spolsky:"
[http://www.joelonsoftware.com/items/2006/06/16.html](http://www.joelonsoftware.com/items/2006/06/16.html)
(well maybe not blame, it's a tradeoff.)

But he mentions it at the end.

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oaktowner
Nice call! I was coming in to post that link, but I see you beat me to the
punch.

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finnh
Classic example of why greenfield development is much more pleasant than
dealing with legacy systems. Of course, you have to do your new dev _well_ to
prevent it from becoming a legacy system that you have to fight with...

But I do think the world of development is just soooo much better now that it
was 10 or 20 years ago. We, as a profession, have much to be thankful for.

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curveship
Given Excel's popularity in the business world, I wonder if an exploit of some
sort could be built into scheduling a transaction for February 29th, 1900. The
date exists in Excel, but not the real world.

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apaprocki
Related anecdote: Interestingly enough, Excel doesn't support dates prior to
the "Excel epoch". I had some genealogical spreadsheets that I had to move to
Google Docs from Excel because Docs supports arbitrary years and Excel treats
anything prior than 1900 as strings instead of dates, losing the ability to
perform date/time operations.

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ttflee
I guess those dates must be treated with greater caution, as the history and
calendar used to be complicated(, not as smooth as UTC time).

[http://www.quirksmode.org/blog/archives/2009/04/making_time_...](http://www.quirksmode.org/blog/archives/2009/04/making_time_saf.html)

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apaprocki
Sure, but I'm mainly talking about using a spreadsheet just as a spreadsheet.
If you enter a bunch of mixed pre-/post-1900 dates into a column and then
change the formatting to display as "DD-Mon-YYYY" everything will change
except the pre- dates. There isn't really anything complicated needed to make
that work, implementation-wise.

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ttflee
Sometimes I feel guilty for not insisting to use 64-bit time stamp for
company's products. Hope anyone keeping those gadgets long enough to hit year
2038 would get sufficient fortune.

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xntrk
How old is the bug? The url says 20 the link and header both say 30.

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Ovid
Yeah, I'm the author of that post and I elected not to change the link after I
changed the title. I love the irony of me originally making a date math error
in the title when the bug was about date math :)

