Saturday is “spring ahead” night, when we advance our clocks an hour before hitting the sack. But, depending on how well we adjust, the sack sometimes hits back.

Georgianna Davies said sleep deprivation was the culprit when she “sprayed deodorant on my hair and hairspray on my armpits.”

Nicolle Toth-Braunberger threw her cordless home phone in her bag instead of her cellphone. “It started beeping as I approached my bus stop so of course I tried to ‘answer it.’ I felt brilliant.”

Tom Royer poured tomato juice on his Cheerios, and Kyle Blake put cat food in the coffeemaker instead of the cats’ dish.

Those are just some of the consequences of sleep deprivation. It could have been worse. A study in the New England Journal of Medicine found an 8 percent increase in traffic accidents on the Monday after shifting the clock, compared with other Mondays.

One hour may be a small change, but when applied to a large population, “there’s a real safety and health issue,” said Dr. Con Iber, sleep program director at Fairview Health Services in Minneapolis.

“If you have to get up an hour earlier, your brain actually is used to still being asleep, still used to being in the restorative process,” Iber said.

“It hasn’t really completed its job.”

Iber said sleep research has grown in the past 20 years, leading to new insights, but also supporting common sense about how cramming overnight for a test doesn’t work. One reason is that sleep actually clears the brain of much of the clutter it accumulates during the day as the connections, or synapses, grow more dense as we process experiences. “At night, we prune those processes, making us more efficient the next day,” Iber said.

A public health epidemic

The Centers for Disease Control and Prevention has called sleep deprivation a public health epidemic, with links to heart disease, obesity, diabetes and other maladies. A recent British study shed more light on this outcome. It found that too little sleep affects the activity of more than 700 genes, some of which monitor the body’s immune system and ability to reduce stress. When these genes are sleep-deprived, they either underproduce or overproduce, according to the study published in Men’s Health. That causes blood cells to change, which then affects the whole body.

Almost one in three adults say they get fewer than six hours of sleep, less than the recommended seven to nine hours. One result: Almost four in 10 reported unintentionally falling asleep during the day, and almost one in 20 said they nodded off while driving at least once in the past month.

No wonder that the National Department of Transportation estimates drowsy driving to be responsible for 1,550 fatalities and 40,000 nonfatal injuries annually in the United States.

Iber said the issue of drowsy driving is further complicated by the fact that “sleepiness itself impairs judgment,” he said. “You don’t know how impaired you are and so you continue to drive.”

The upshot is that getting enough sleep doesn’t only make you feel better, but contributes to public safety. “It’s really our social responsibility to sleep,” he said.

The “fall back” to Standard Time is easier than the “spring ahead” because we regain that lost hour, and it’s easier to stay in bed for another hour than to get up an hour earlier.

Saving more time

The whole concept of “saving” daylight began during World War I as a way to preserve fuel by needing less illumination at night. The practice varied until 1966, when the Uniform Time Act provided a standard model. For years, DST began on the first Sunday of April and ended on the last Sunday in October.

But in 2007, Congress changed it to begin on the second Sunday of March. It will end the first Sunday in November.

Iber said it’s possible to ease into the spring shift by going to bed 15 minutes earlier each night in the week leading up to the change, although he acknowledged that it’s difficult to go to bed early. At the very least, plan to be more aware of your surroundings next week, taking more care while driving and watching out for other drivers.

And get some sleep. The only honking sound anyone should hear should be your snores.