Did your high-tech clock turn itself back on Sunday? Or did you turn it back yourself? If so, you were probably an hour late for church, or the fox hunt, or whatever else you planned for the day.
For the first time since 1966, when the Uniform Time Act decreed a nationwide return to standard time on the last Sunday in October, daylight saving time will end this year on the first Sunday in November.
The switch should not have surprised anyone. It had been coming since Congress authorized it in the Energy Policy Act of 2005.
And the new regime really began last spring, when the start of daylight saving time was moved up by three weeks - to the second Sunday in March instead of the first Sunday in April.
That switch had more advance promotion - and got millions of Americans to download software patches or adjust their computer clocks and other devices to accommodate the change.
But the change involved both ends of the season. So the delayed end to daylight time this fall surprised those who missed it the first time around, or forgot. It affected electronic systems from clock radios to BlackBerries to thermostats. Many of the devices turned their clocks back Sunday morning, a week too early.
Now, Americans are rummaging in their junk drawers for their owner's manuals.
In Baltimore, no one remembered to reprogram the city's Easy Park parking slip dispensers, so some drivers got tickets when their time expired an hour too soon. The Parking Authority has promised to abate any tickets issued before the machines were reprogrammed from the system's central computer.
Elsewhere, reports were trickling in about similar slips by our electronic tools and toys and their keepers. Here and there, bank clocks reset a week early. BlackBerry portable e-mail devices rolled back an hour, while office phone systems, computers and programmable thermostats did the same and had to be reset by hand.
But it wasn't an avalanche. "So far we've gotten, I would say, 1 percent of the number of questions and complaints we had in the spring" when daylight time began early, said Tom O'Brian.
O'Brian is chief of the Time and Frequency Division of the National Institute of Standards and Technology. That's the government office in Boulder, Colo., whose timekeepers control the atomic clocks that set the pace for every other clock in the country - and much of the world.
For people whose clocks, watches, video recorders, computers and phone systems are automatically time-controlled by the NIST's radio or Internet time signals, the switch to standard time should occur on time Sunday morning.
But for some, there was a catch, O'Brian said.
"We are providing time [signals] for computers all over the world, and we have no way of knowing whether you're calling from Baltimore or California or India." So, NIST delivers the time as Coordinated Universal Time, once known as Greenwich Mean Time, or Universal Time.
That leaves it up to the end device - the computers and phone systems and such - to correct for the local time zone and any changing daylight saving time rules.
And that means it's up to you, your office information technology expert, systems administrator or your grandchild to reprogram your computers or other devices to recognize the new changeover dates.
"Having gone through a change in the rules in the spring, most people that had devices that might be affected have probably taken steps to ensure they will be working now," O'Brian said.
The biggest worry last spring was that big IT systems might not be reprogrammed in time. But that much seemed to go smoothly.
"I was not aware of any big effects on financial or transportation systems," O'Brian said. "People had ample warning and had updated their operating systems. And manufacturers have provided updates or patches."
Systems administrators for large corporate phone networks and cell phone systems probably got it right the first time, he said.
Home computer users with Windows XP or Vista, or MAC owners running OS X, also had the correct adjustment downloaded if they kept their operating systems up to date.
Most home users with older systems probably made the adjustments in the spring. "But I wouldn't be surprised if a few folks didn't update," O'Brian said. "They may still find themselves with an outdated system."
If so, help is available. Microsoft offers a software patch at http:--microsoft.com/windows/timezone/dst2007.mspx.
Patches for other operating systems may be found at http:-- calconnect.org/dstlinks.shtml.
Similarly, Research in Motion, maker of BlackBerry devices, has time-change patches available at http:--blackberry.com/select/dst2007.
Fixes for some other daylight time glitches may be as hard to find as the devices' owner's manuals. Consider clocks and clock radios marketed as "Smart Set" or "Auto Set" devices.
"Their clocks have a built-in way to keep track of the time if the power goes out, and to auto-change between daylight and standard time. If you bought the older version, you might find the clock still runs on the old rules," he said.
If so, there's not much you can do about it except change the time-zone setting to Central Time for a week and then back to Eastern Time on Sunday. (And to Atlantic Time for three weeks in the spring.) Repeat each year, forever.
"Or, you could ask the manufacturer to supply you with a new clock," he said.
The good news? In its 2005 legislation, Congress reserved the right to change the whole system back to the old dates if the Energy Department finds the new regime didn't save enough energy. Or, if people hate it.
"I won't be surprised if we see changes again in the future," O'Brian said.