Microsoft confirms April Fool's bug

A bug reported by a Massachusetts programmer will cause some Windows applications to behave as though it were one hour earlier than the correct time shown on the operating system's clock. That could lead date-book entries to slip and Windows-based banking systems to record the wrong time for financial transactions. "It's unusual, because it's so pervasive," said Richard Smith, president of Phar Lap Software, who discovered the bug and published it in an industry list called NT Bug Track last week. "It's going to hit every Windows PC in the U.S. -- not every application, but a fair number will have the problem."

Smith traced the bug to a library file that checks when to start daylight savings time. The fact that April 1, 2001, falls on a Sunday confused an algorithm within the file, which leads to a one-week delay in beginning daylight savings time. A simple patch should fix the file -- MSVCRT.DLL -- but some applications contain their own copies of the library, and those applications would have to be repaired by each software vendor, Smith said. On his own PC, for example, he found 10 copies of the file.

"The problem is, you can't fix it yourself, you must get new software," he said. "Not all the applications have the bug, so if you set your clock an hour ahead, that would fix some applications but break other ones. It's very frustrating."

Microsoft Corp. confirmed the bug, but said in most cases a repair would be no problem. "Ninety-nine percent of all packaged applications... can be fixed really simply by downloading a new version, or a patched version, of the DLL," said Chris Hargarten, a product manager on Microsoft's Visual C++ team.

He said the company is investigating the issue and "is working on the timing" of a fix.