Most people remembered to set their clocks ahead last night so they could spring forward today into daylight saving time, the harbinger of spring and summertime.
But for some, it can cause headaches, irritability, tiredness and poor concentration.
"They keep moving it up. I think it's too soon. We're still in winter and it's dark early in the morning in March," said Burbank psychologist Deborah Lakeman. "Most animals gear their cycle to the sun without alarm clocks. It affects our mood."
To save energy, Congress moved the start of daylight saving time to the second Sunday in March 2006. Before then, it started on the first Sunday in April.
On Monday, the sun will rise at 7:06 a.m. So, when the alarm goes off at 6:45 a.m., adults will look incredulously at their clock and moan because it will still be dark. Teenagers and young children will not want to get out of bed until the sunlight is streaming into their rooms. But that won't happen until April 4, when the sun will rise at 6:37 a.m., according to timeanddate.com.
The American Psychological Assn. in 2009 reported that fatal car accidents and workplace injuries increase on the Monday after the time change. A study by Swedish researchers published in the New England Journal of Medicine found that heart attacks increase for a very small number of people (5%) in the first three workdays.
"The question is why does this occur?" said cardiovascular expert Dr. Gerald Pohost, the head of Glendale Adventist Medical Center's Outpatient Cardiac Imaging Center. "It may have more to do with other factors, such as the stress of traffic or pre-existing health conditions."
Recent research links sleep deprivation to an increased risk for high blood pressure, inflammation and obesity, all of which are considered risk factors for heart attacks. But Pohost is not convinced that losing one hour of sleep will cause a person to have a heart attack.
Pohost also questioned whether the findings of a study conducted in Sweden, where winters are harsh and dark, can be applied to Southern California residents.
"Here, nothing really changes. I see more health benefits. We do have more sunshine in the evening, which, in turn, could give us more Vitamin D. We know that Vitamin D can help reduce the incidence of heart attacks," he said. "And an evening walk could reduce stress and improve fitness."
"Most people really enjoy daylight saving time," said neurologist Dr. David A. Thompson, the sleep expert at Glendale Adventist Medical Center. "It affords them some remaining light to be physically active."
Exercise, he added, is great for sleep, but strenuous exercise should not be done two to three hours before bedtime because it increases the body temperature, which keeps us awake.
Thompson said the time change could be difficult on those people with insomnia or other chronic sleep disorders.
The key to avoiding problems, he said, is the "anchor of a good night's sleep." The "anchor" is getting up at the same time in the morning. But then make up the "lost" sleep by going to bed 15 minutes earlier for four days.
"You can't make it up in one night," he cautioned. "If you go to bed an hour earlier, you'll just lie in bed, get frustrated and not be able to fall asleep."
For most adults and children, the grogginess, irritability and tiredness caused by the change and the body's reaction to having less light in the morning and more light in the evening will disappear within a week or so.
The National Sleep Foundation last week reported that its 2011 Sleep in America poll found pervasive use of communications technology in the hour before bed, costing Americans the sleep they need.
Lakeman and Thompson agreed that the artificial light emitted from computers is interpreted by the brain as natural light, meaning it will wake you up.
"You have to shut off the computer one hour before you go to bed, and give yourself some quiet time so you can fall asleep," Lakeman said.
Tips for Adjusting to daylight saving time
* Go to bed 15 minutes earlier for four nights following the start of daylight saving time to make up the hour lost.
* Upon arising, open the window blinds and let the sun shine in. Early morning light exposure can help you make the shift because it's a powerful signal to your body that it is time to wake up.
*If you are having trouble with your sleep cycle at the start of daylight saving time, avoid the extra evening light until your body adjusts. Stay inside and draw the blinds for those first few nights.
*Aromatic eye masks scented in lavender may help you fall asleep.
*Move it, move it. Regular exercisers sleep better. But keep vigorous exercise to early in the day. Exercising too close to bedtime can keep you awake. A relaxing evening walk helps burn calories and reduces stress.
*Gentle stretching and yoga shortly before bedtime can help you relax your mind and relieve muscle tension.
*Turn off the electronic devices 60 to 90 minutes before bedtime. No computers, no cell phone texting.
*Television, which is a passive activity and viewed from a distance, may be watched before bedtime, but nothing that will get your heart pounding. Record the exciting shows and watch them another day well before bedtime.
*Even though they have to wake up early for school, young children will resist going to bed when it is still light outside. Reading to the child in a dimly-lit bedroom may help the child to fall asleep.
Compiled by Vicki Smith Paluch