Daylight-saving time comes earlier this year, which has forced online brokerages to update systems that are programmed to automatically reset their clocks in three weeks to ensure trades are executed at the right time and price.
Though many financial companies handle time-sensitive transactions, an hour's difference can be especially significant for brokerages, because mistimed stock trades could potentially lead to substantial losses for their clients.
Daylight-saving time has historically started on the first Sunday in April. Beginning this year it starts on the second Sunday in March because of the Energy Policy Act of 2005, which was designed to reduce energy expenditures.
Charles Schwab Corp. says it is in control of the situation. "We've had a dedicated technology team here working on the initiative for several months," said Glen Mathison, a spokesman for the San Francisco firm. "We expect the transition to go smoothly, without any interruption to client service."
Mr. Mathison said vendors are supplying patches to their software, and "we've obtained all of the necessary patches we've needed."
But "our work isn't completed until we work through the change and have tested all our systems," Mr. Mathison said. "We're going to have extra staff in place" to perform those tests and work on any problems when the clock shifts on Sunday.
Kim Hillyer, a spokeswoman for TD Ameritrade Holding Corp., said the Omaha company will have "all hands on deck" for the time change. It began patching its software in November, and though it is still working on some systems, the work to guarantee the timing of trades is complete, she said.
Both Schwab and TD Ameritrade say that they are prepared to help customers but that they have received few inquiries.
Julien Courbe, a managing director at BearingPoint Inc., a consulting firm in McLean, Va., said unprepared companies could face severe disruption. "We're actually talking about a small Y2K," he said, referring to the scramble to update computer systems as their internal clocks rolled over to 2000. "I think overall the industry moved fairly late," he said, though he would not name any of his clients.
Mr. Courbe said that if brokerage software is not updated, "you would have the wrong time, and then you would have the wrong quote" for trades.
Schwab's Mr. Mathison did not think the Y2K comparison is appropriate, because the adjustments for daylight-saving time are much easier to make. "The changes that had taken place for Y2K were far more wide-ranged."
TD Ameritrade's Ms. Hillyer agreed that "it's a much simpler transition" than Y2K. "With Y2K, there was a lot of hard code changes," which is not the case for this change.
Rodney Nelsestuen, a senior analyst at TowerGroup Inc., a Needham, Mass., independent research firm owned by MasterCard Inc., said that though the problems may be easier to address, their source is similar: "Who knows what some programmer did 10 years ago?" he said.
There may be less hype now - Y2K "was going to be the end of time as we know it," he joked - but some companies have been less proactive about this change, Mr. Nelsestuen said. Some vendors "woke up one day and said, 'Gosh, we need to patch.' " Though banks and vendors had two years' notice, "it's easy to fall off the radar screen" in that time, he said.
"What it does point out is a need for change management," and Schwab's keeping extra staff on hand over the weekend is an example of good change management, Mr. Nelsestuen said.
"It's not just something that somebody's going to throw a switch at," he said. "It's not painless."
Brokerages need to be vigilant about even minor lapses "in this litigious world," he said, but if they keep a team available, "that will diminish the legal liabilities that are out there," because they would be able to show they were on top of things during the transition.
