Last night I went around the house setting the time on the clocks, that don't automatically adjust, back an hour. I remember that every clock had to be adjusted manually. Then in college, I bought an VCR that automatically adjusted itself. At that time, Mac OS didn't automatically adjust for Daylight Saving Time. So, I wrote the Set Daylight appe to adjust the time. This was pretty easy to do, since the rules for the dates that the time adjustment occurred, were static. This was added to Mac OS 8, so it wasn't necessary anymore.
But now most electronics include support to automatically adjust for Daylight Saving Time. For example, TiVos, Mac OS X, Windows and Linux PCs, and PDAs will automatically adjust. Now that the days that Daylight Saving Time is changing, all of these devices have to be update in order for the time to be correct.
I like the way that iHome iH5 and the iHome IH36 have dealt with this. They both have a switch, on side labled '-1', and the other '+1'. When you want to set the clock back an hour for Daylight Saving Time, move the switch to '-1'. So they don't have to update the device when the US decides to change the start and end point of Daylight Saving Time.