Clocks spring ahead for daylight saving time this weekend

If you've been longing for the days when the sun isn't already setting as the workday ends, wait no more. It's time to spring ahead.

Daylight saving time begins at 2 a.m. Sunday. That's when we set our clocks ahead one hour, leading to more light in the evenings.

Yes, we lose an hour of sleep this weekend. But we will get it back in November, when the clocks are set back again as daylight saving time ends. And yes, it will be darker as we head to work and school in the mornings.

Daylight saving time "has the effect of moving one hour of daylight from the morning to the evening," says the National Institute of Standards and Technology, the official timekeeper for the United States.

Unless, of course, you live in one of the areas where the time switch doesn't apply. Hawaii, American Samoa, Guam, Puerto Rico, the Virgin Islands and all of Arizona except the Navajo reservation do not observe daylight saving time.

We spend more of the year in daylight saving time than we used to. In 2007, the period was extended for one month in an effort to reduce energy consumption.

Daylight saving time now runs from 2 a.m. on the second Sunday of March until 2 a.m. on the first Sunday of November, a 238-day span that covers 65 percent of the year.

Though our evenings may have more sunlight, not everyone is a fan of the dark mornings to come.

Sixty-one percent of adults surveyed by the Better Sleep Council, a nonprofit that supports the mattress industry, say they feel the effects of the switch the Monday after resetting their clocks. And 11 percent say it takes them more than a week to get back to normal.

Many fire departments use the twice-a-year clock changes to encourage people to check their smoke alarms.

Philadelphia Fire Commissioner Lloyd Ayers and Renee Cardwell Hughes, chief executive of the American Red Cross of Southeastern Pennsylvania, are visiting a senior center in East Mount Airy today to encourage residents to check alarms.

Ayers and other firefighters will also visit homes throughout the city today, Saturday and Sunday to install alarms and distribute fire-safety information.