Union Democrat staff

Daylight saving time begins at 2 a.m. Sunday.

This is also a recommended time to do some home safety maintenance.

Federal law specifies that daylight saving time applies from 2 a.m. on the second Sunday of March until 2 a.m. on the first Sunday of November in areas that do not specifically exempt themselves. Arizona and Hawaii do not use daylight saving time.

The adage "spring forward" means setting clocks ahead one hour when daylight saving time begins in spring. The drill is reversed in fall.

Most people set their clocks ahead before going to bed Saturday.

The National Institute of Science and Technology maintains the atomic clock, dictating the official U.S. time. It contributes to world time, called Coordinated Universal Time. The institute must comply with daylight saving time and explains it has the "effect of moving one hour of daylight from the morning to the evening."

All NIST time services broadcast Coordinated Universal Time. Adjustments for local time zones and for daylight saving time are provided within many computer operating systems.

Cal Fire, the state's chief firefighting agency, recommends maintaining home safety alert devices with the time change. Homeownersshould change the batteries in their smoke detectors and carbon monoxide detectors at the start and finish of daylight saving time.

Lisa Williams, spokeswoman for Cal Fire's Calaveras-Tuolumne Unit, also recommends vacuuming the devices for dust and debris that may interfere with operation.

Carbon monoxide detectors are required by state law, as of 2011, in single family homes with attached garages and/or fossil-fuel sources for heating. Williams added families should establish a planned escape route for emergencies and maintain home defensible space.

Tuolumne Utilities District also recommends sprinkler system maintenance be on the calendar with the time change.

"With more daylight time approaching and with spring just around the corner, it's the perfect time to check all your irrigation and lawn systems before they are put into use," said Lisa Westbrook, district spokeswoman.

This includes checking and replacing batteries, checking timer settings to adjust for daylight saving time, and settings for number of days and minutes the system is watering, she said.