Spring forward, plan ahead

How severely will the change in daylight-saving time affect IT systems? Worse than you might think, according to one observer.<@SM><@SM><@SM><@SM>

How severely will the change in daylight-saving time affect IT systems? Worse than you might think, noted Bob Mitchell, senior vice president and CIO for government systems provider GTSI.This year, for the first time ever, daylight-saving time will take effect on the second Sunday in March, two weeks earlier than in previous years. And in the fall, DST will end on Nov. 4, a week later than previously.While most major applications that rely on accurate timekeeping have probably been , a number of second-order effects may plague administrators if they are not careful, Mitchell noted."It is not as simple as the vendor updating its server operating system and then everything will be fine," he said.For instance, the widely used Kerberos computer network authentication protocol requires two machines that are communicating to report the same time, at least within the range of five minutes. "If you patch every system except the one associated with validation, you could end up refusing every authentication in the network," Mitchell said. "Business could get shut down over this if they didn't properly patch."The good news is that most vendors have updated their software, either through new releases or patches, to accommodate the new time spread. Administrators who have been applying the patches consistently should be ready to go. Mitchell also noted, though, that even if you've installed the patches early, you may want to recheck for updates. Many companies, such as Microsoft, have updated their patches since their initial release.In most environments, it is the OS that keeps track of the time. In network environments, the OS periodically downloads the Coordinated Universal Time, or UTC, from Internet time servers. The OS itself then adjusts for local time, including any fluctuations due to changes such as DST.And by and large, OS vendors have addressed the DST change fairly early on, at least for recently released OSes.In December, Sun Microsystems Inc. to adjust earlier versions of Solaris that do not already incorporate the time changes.On the Linux front, the major distributors seem to addressed the issue as well, including , and .Likewise, Microsoft and/or written the changes into the newer releases of its OSes. Take note though: Many of the older operating systems will not be updated. Remaining unpatched are Windows NT, copies of Windows XP without at least Service Pack 1 and copies of Windows 2000 without extended support.With the OS patched, the administrator should then look at any applications that may keep time internally, rather than getting it from its host OS.While the vast majority of applications rely on the OS for time info, a few do not. Java applications, in particular, , rather than those provided by the OS. Sun recommends updating the client JRE but provides a patch where that is not feasible.Vendors are also supplying fixes to address this problem at the software development level. Sun updating some of the older libraries included in Sun and Forte developer software. Oracle has noting that a small number of users of its E –Business Suite may be affected by the change.On the Microsoft side of the house, NET and C++ applications built with custom classes for handling time zone information as well.According to the on DST, a fair number of other products will not automatically adjust for the new time as well—including Cisco Systems' , devices, , and a ."I think this crept up on everybody, including the people who make this equipment," Mitchell said. Few "realized how much dependency a simple hour time change has."

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