In March of 2007, the US Government changed the months for daylight savings time from April through October to March through November.
Under the new guidelines, daylight savings time starts on the second Sunday of March and ends on the first Sunday of November. In 2007, these dates were March 11th and November 4th.
If you have an older DST clock, chances are that the movement in the clock has the "old" daylight savings effective dates programmed into it (April through October). The quartz movement will continue to keep time properly, but you will need to turn off the "DST" function so the time does not automatically change on the "old" or wrong daylight savings dates.
CLICK HERE to view the instructions for turning off the DST function of your clock.