The vernal equinox signals the beginning of nature’s renewal. Birds begin migrating northward. Worms emerge from the earth. We put winter clothes away, and turn off the furnace. At approximately (and I mean approximately) the same time each year most Americans will "spring forward" for Daylight Savings Time, DST.We shift our watches and clocks one hour earlier, all except parts of Arizona and Hawaii who do not observe Daylight Savings Time.A little trivia: As of 2007, daylight savings time begins in the United States on the second Sunday in March and e