Spring Forward: Here we go again with Daylight Savings Time

Are all of your computers, applications and devices ready for tonight’s Daylight Savings Time changeover? If you’re in the United States, the answer probably is “no.”

In its infinite wisdom, the U.S. government changed the rules for Daylight Savings Time in 2005, to take effect in 2007. Most modern software systems have been updated, but not everything has been.

Here are the rules for this year and next, for those U.S. states which observe DST:

Standard Time begins each year at 2:00 a.m. (local time) on the first Sunday of November.

Move your clocks back one hour at the resumption of Standard Time.

In 2008, DST is from 2:00 a.m. (local time) on March 9th until 2:00 a.m. (local time) on November 2nd.

In 2009, DST is from 2:00 a.m. (local time) on March 8th until 2:00 a.m. (local time) on November 1st.

Before the 2005 legislation, DST begin on the first Sunday in April, and ended on the last Sunday in October. So, there’s a good chance that for the next few weeks, your home or office will have some devices or applications that won’t pick up the DST change, and thus they’ll display the wrong time for nearly a full month, from March 9 through April 6.

Don’t forget: Tonight, at 2:00am on Sunday, change all your clocks forward to 3:00am.

Stefan Klein wrote a nice piece about Daylight Savings Time in the New York Times.