Daylight Saving Changes in 2007 and the Impacts

by Jeff Regan

In 1999, there was much concern about the impact of software's inability to switch from years starting with 19 to years starting with 20. A lot of effort was put in place to virtually eliminate the issue by the time the year 2000 came along.

There is a new risk for many businesses that has some similarities to the Y2K bug, but is not actually a bug at all.

Last year, in an attempt to reduce energy consumption, the US Congress, in section 110 of the "Energy Policy Act of 2005" announced plans to move the start and ending dates of Daylight Saving time to give more light in the evenings for a longer period of the year. All of Canada (except the regions that never change their timezone at all during the year) will follow the U.S. plan as well. Bermuda has announced a similar plan.

In 2007 (and the years following), Daylight Saving Time will start on the second Sunday of March instead of the first Sunday of April. It will end on the first Sunday in November, instead of the last Sunday in October.

Businesses, and individuals who use any hardware or software that is sensitive to date and time transactions, and utilizes a local time zone, or interacts with systems that use a local time zone (versus the universal UTC time zone used for many world wide business transactions) could be impacted by these changes in Daylight Saving Time.On your typical computer server or PC, the automatic decision to change to Daylight Saving time is generally made by the underlying Operating System, such as Microsoft Windows or Unix. However, applications often also perform date and time manipulation, and may make a similar automatic decision, or use date/time calculations in other ways.