Signed into law in August 2005, the federal Energy Policy Act of 2005 moved the start of DST from the the first Sunday in April to the second Sunday in March and delayed the return of standard time in the autumn by a week, to the first Sunday in November. The idea: Shifting the time change by a few weeks can save on energy use.

For IT, that means every software and hardware system relying on time stamps should now be checked, evaluated and tested -- and, if need be, patched with software updates or modified to work properly. But with a wide range of security issues, compliance requirements, spam-fighting efforts and other concerns already on their to-do lists, many IT administrators are only now evaluating what the DST change will mean and how they need to respond.

Gartner Inc. issued a statement today urging companies to take the issue seriously, saying "disruptions at an IT infrastructure and application level are likely" and "will have significant implications for organizations around the world." The Stamford, Conn.-based research firm said interruptions could affect calendaring applications, billing software and security programs as well as travel and trading schedules.

"This is a minor problem compared to the big code changes required in the recent past for issues like Y2k or the euro conversion," said Will Cappelli, an analyst at Gartner. "However, significant business damage and liabilities, as well as nuisance, could occur from applications performing their processing at the incorrect time if organizations do nothing."

In the meantime, the clock is ticking.