Lynda Zelesnak, age 15, of Koppel, Pa., for her question:

WHY DO WE HAVE DAYLIGHT SAVING TIME?

Daylight saving time is the plan where clocks are set one hour ahead of standard time for a certain period. Darkness, therefore, comes one hour later, giving the advantage of one extra hour of daylight each evening.

During World War I England adopted daylight time as an economy measure. In 1918 the United States also adopted it, but the U.S. Congress repealed the law in 1919.

After World War II daylight time was used in many individual states. An act of Congress in 1967 established daylight time from the last Sunday in April to the last Sunday in October. A state may remain on standard time, however, if its legislature votes to do so. In 1974 and 1975 daylight time was extended into winter months in an effort to conserve energy.