Change In Daylight-Savings Time Could Cause Headaches For Building Systems

The Energy Policy Act of 2005 (EPAct), a comprehensive package of energy legislation setting new rules for everything from offshore oil exploration to energy consumption in commercial buildings, includes a little-discussed change that could create major headaches for computer-controlled building management systems and other date-sensitive technologies throughout the United States six weeks from now.

EPAct extended the length of daylight-savings time (DST) by about four weeks. The legislation moved up the start date for DST to the second Sunday in March instead of the first Sunday in April, and extended the change back to standard time to the first Sunday in November instead of the last Sunday in October. The change is to take effect this year, on March 11.

The change is intended to reduce energy consumption by increasing the number of daylight hours during the “waking day” over a longer period.

Advocates of the change during the debate on EPAct legislation said the longer DST period could cut total energy consumption by as much as 1 percent during March and April. These statistics, based on a 1970s study, are disputed by some observers who point to a study during the 2001 California energy crisis that indicated DST mostly just shifted energy usage to a later part of the day.

EPAct specifies that a study following the change will determine whether it returns the expected energy-saving benefits. If not, the dates could be changed back.

The more predictable result is a lot of confused computer systems and confused people.

“There will be a lot of people who will get up that Sunday morning, get their coffee, get dressed and go off to church or to open a store, and will find that the lights aren’t on,” said Scott Jordan, product marketing manager, Square D/Schneider Electric, Pallatine, Ill.

When that happens, many will go into their control systems and manually set the clock forward, only to have the system reset it forward another hour on April 1. “They’ll have to change it around again, or have their systems an hour off all summer,” Jordan said. And from Oct. 28 to Nov. 4, the same scenario plays out in reverse.

The effect on building management systems, lighting systems, metering products, security systems, programmable thermostats and any other technology programmed to adjust or record events according to the clock will cause problems similar to the Y2K issue of 1999, though on a much smaller scale.

The amount of work needed to prevent this confusion will vary according to how an individual system sets the dates for DST changes. Building management systems incorporate one of three different approaches, said Jordan.

Some older systems still have dates set in their hardware on read-only memory (ROM) chips soldered into their circuit boards. These will require a hardware fix, a replacement of the existing chip with a new chip programmed for the new DST effective dates.

Dates and times on some other systems are set in firmware at the basic-input-output system (BIOS) level. These can be downloaded into programmable memory and fixed with a software patch.

The third variant comes in systems where dates are set in the software itself, where the change is simply a matter of reprogramming the dates of the DST change.

Computer systems that receive automatic software updates online or that synchronize to an Internet-based standard clock will be able to incorporate the change with no intervention by users.

Many software companies, such as Microsoft Corp., Redmond, Wash., have information on their websites advising users of the need to change and guiding them through the process.

Jordan sees an opportunity here for manufacturers, distributors and contractors who make, sell and install building management systems to step forward and prepare customers for the change.

“They can call their best customers and say, ‘We might want to inventory what kind of systems you’ve got that will be affected by the change. We’ll work with you to identify the equipment, then work with the manufacturers to get all the changes taken care of,’” Jordan said. “There’s an opportunity here to be on the front side of this thing and turn it into a customer-service advantage.”