Although the changes to DST became federal law in August 2005, it has only been in the last few months -- or weeks, even -- that many companies have to prepare their systems for the new starting and ending dates. As a result, the situation remains unsettled, according to interviews with IT managers, consultants and analysts.

Ray Wang, an analyst at Forrester Research Inc., said IT clients are jamming the consulting firm's phone lines asking for advice about what they should do. "A lot of customers are still not ready because a lot of the vendors released their patches late," Wang said. He added that the early time change is turning out to be "a bigger deal than vendors and customers had expected."

DST, which previously began during the first weekend in April, will take effect at 2 a.m. on March 11 this year. That means IT systems have to be updated or modified to reflect the proper time for applications that rely on time stamps, as well as for tasks such as scheduling. But a problem now often cropping up, Wang said, is that patches from one vendor are causing code mismatches with other applications that then also have to be resolved.

"There are patch compatibility issues," Wang said, citing Microsoft Corp. as an example. "There are cases where even Microsoft has released three different patches in the last few months" to resolve problems that the first ones caused with other applications, he said.

Rudy Ebisch, assistant director of the infrastructure group at a large manufacturer of home and office products that he asked not be identified, said his IT team is about 95% finished with a long list of system checks on the company's nine major software platforms. "Nothing has been a showstopper," he said.