In a recent study, the physicians have come to a conclusion that daylight time, holidays and anniversaries increase the risk of heart attack.

The research also found that there is 5% decrease in heart in heart attacks and hospitalizations after the clocks are reset to standard time.

Dr. Ralph Brindis, Vice president at the American College of Cardiology, who practices in Oakland said, "This study is fascinating."

The factor behind heart attacks is sleep deprivation which causes higher blood pressure, heart rate and the tendency to form dangerous clots.

Following the tradition of setting the clocks according to the DST, two Stockholm-based epidemiologists who study the relationship between heart attacks and sleep decided to investigate the effect of moving into and out of daylight saving time.

It was then that Dr. Imre Janszky of the Karolinska Institute and Dr. Rickard Ljung of Sweden's National Board of Health and Welfare started examined data from the Swedish Myocardial Infarction Register, a catalog of all heart attacks in Sweden that resulted in hospitalization or death. They found that there was 5% decline in heart attacks when daylight saving time ended.

According to Rickard Ljung, MD, PhD, "We know that Monday is the most dangerous day for heart attacks." Mr. Ljung further added, "It has been thought that this is due to the stress associated with returning to work after the weekend, but our study suggests that disturbed sleep rhythms may be involved, and that the extra hour of sleep we get in the fall [after daylight saving time ends] may be protective."

However, Northwestern University professor of preventive medicine Martha Daviglus, MD, is not convinced about the impact of isolated events like daylight saving time on increased heart attacks.

"I wouldn't want people to get the idea that losing one hour of sleep will cause them to have a heart attack," she says.