Fire officials are urging residents not just to set their clocks ahead one hour this weekend, but also to change the batteries in their smoke alarms and carbon monoxide detectors.

Daylight saving time officially begins at 2 a.m. Sunday morning. The International Association of Fire Chiefs has promoted battery changes on the time-change weekend for more than two decades.

Fire codes require that all Las Vegas homes built since 1994 have smoke alarms wired to the home's electrical supply and have a battery as a backup power source. Homes built before 1994 may only use the battery.

Firefighters say smoke alarms have reduced fire fatalities by about 50 percent. About 3,800 people died in fires in 2010 in the United States.