Daylight Savings Time Fail
The Buggy Radio-Controlled Clock
A Technology Challenge
The start of Daylight Savings Time in the United States always poses a
challenge for my radio-controlled clocks.
I own two such clocks. Both failed to adjust automatically to the start
of Daylight Savings Time last Sunday. These clocks were manufactured in
2004, before the current DST dates were adopted, so any pre-programmed
dates are wrong. In theory, the WWVB radio signal should inform the
clocks when to switch to Daylight Savings Time, but this feature had not
been adequately validated by the manufacturers.
On the clock in the photo, I manually pressed the synchronize button to
work around the off-by-one error in the clock's firmware (the
automatic DST adjustment occurs one day too late). On the other clock,
I previously had turned off automatic DST adjustment (because it was
buggy), so I turned it back on.
That fixed the immediate problem of the clocks telling the wrong time
for most days. There is still the long-term problem that I own two
clocks that tell the wrong time on two days of the year.
Foreshadowing the Internet of Things
Adjusting the radio-controlled clocks has become a yearly ritual in my
household, just like conventional clocks. By now, I regard the
manufacturers' claims of "World's Most Accurate Clock" and
"Never Needs Setting" as reflecting the naive optimism of someone
who has never encountered a computer.