{"id":3809,"date":"2012-12-17T00:01:59","date_gmt":"2012-12-17T07:01:59","guid":{"rendered":"http:\/\/www.wambooli.com\/blog\/?p=3809"},"modified":"2012-12-17T00:09:40","modified_gmt":"2012-12-17T07:09:40","slug":"february-29-1900","status":"publish","type":"post","link":"https:\/\/www.wambooli.com\/blog\/?p=3809","title":{"rendered":"February 29, 1900"},"content":{"rendered":"<p>Don&#8217;t bother looking it up. Nothing significant happened on February 29, 1900. No one was born, no one died. While that may seem extraordinary, it&#8217;s true because there was no February 29, 1900. That is, unless you use Microsoft Excel.<br \/>\n<!--more--><br \/>\nFebruary 29 is a legitimate date. It&#8217;s leap day! It happens once every four years, coinciding with a Presidential election year here in the US.<\/p>\n<p><em>But 1900 was a Presidential election year!<\/em><\/p>\n<p>Yes, it was. A belated congratulations to President McKinley who, unfortunately, died in office just over a year later. That had nothing to do with February 29th, however, which didn&#8217;t happen in 1900.<\/p>\n<p>Leap years don&#8217;t occur in years divisible by 100 but not divisible by 400. So the year 2000 was a leap year, but not the year 1900.<\/p>\n<p>My point is not to bewilder you, but to state again that there wasn&#8217;t a February 29, 1900. It doesn&#8217;t exist anywhere but in Microsoft Excel, where you can perform time calculations based on that date.<\/p>\n<p>That begs the question of how Microsoft would bother to let such an obvious error slip? After all, wouldn&#8217;t you want to accurately calculate the interest you&#8217;d have to pay on a new buggy loan you took out in 1887?<\/p>\n<p>Sure you would!<\/p>\n<p>The problem isn&#8217;t with Excel. In fact, Microsoft knew darn well that February 29, 1900 wasn&#8217;t a legitimate date when they first coded Excel. No, the problem was with Excel&#8217;s direct and quite popular ancestor, a program called Lotus 1-2-3.<\/p>\n<p>Lotus 1-2-3 was effectively the first &#8220;killer app&#8221; for the PC. It took over from the original spreadsheet program, VisiCalc, which was popular way back in the early steam-powered days of personal computing. But VisiCalc isn&#8217;t to blame.<\/p>\n<p>It turns out that February 29, 1900 was coded as a legitimate date in 1-2-3. I don&#8217;t know how that oversight managed to make it into the program, and I certainly don&#8217;t want to know how the math works. Once the error was discovered, it couldn&#8217;t be fixed: Too many existing spreadsheets depended on it. So in the fine tradition of legacy computer programming, the error remained.<\/p>\n<p>When Excel was introduced, itself an offspring of Microsoft&#8217;s original spreadsheet, Multiplan, they incorporated the February 29, 1900 date error. After all, Microsoft wanted to maintain 1-2-3 compatibility and didn&#8217;t want to risk screwing up date\/time calculations in existing spreadsheets, especially on buggy loans. Therefore the problem persists, even to this day.<\/p>\n<p>And it will probably persist forever, given that &#8220;maintaining compatibility&#8221; is one of the cornerstones of computer software ideology. So, real or not, February 29, 1900 never happened but it will probably be with us for all eternity &#8212; or until the Robot Apocalypse. But even then, the robots will probably be programmed with Excel, so the date most likely will never go away.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Don&#8217;t bother looking it up. Nothing significant happened on February 29, 1900. No one was born, no one died. While that may seem extraordinary, it&#8217;s true because there was no February 29, 1900. That is, unless you use Microsoft Excel.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[],"class_list":["post-3809","post","type-post","status-publish","format-standard","hentry","category-main"],"_links":{"self":[{"href":"https:\/\/www.wambooli.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/3809","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.wambooli.com\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.wambooli.com\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.wambooli.com\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wambooli.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3809"}],"version-history":[{"count":8,"href":"https:\/\/www.wambooli.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/3809\/revisions"}],"predecessor-version":[{"id":3831,"href":"https:\/\/www.wambooli.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/3809\/revisions\/3831"}],"wp:attachment":[{"href":"https:\/\/www.wambooli.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3809"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.wambooli.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3809"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.wambooli.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3809"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}