Puerto Vallarta, Mexico - There's just a couple of days left before we get that opportunity for an extra hour's sleep in the morning. That's right, daylight saving time 2012 officially ends for most of Mexico at 2 am on Sunday, October 28th - this weekend! That means you need to set your clock back one hour.

Since Mexico did not go along with the changes that the United States made to established daylight savings time in 2007, it's important to note that the shift to standard time in Mexico will take place a week earlier than in the US, something visitors may find useful to know - especially those arriving by cruise ship or airplane.

Equally important, it is also a good time to check the batteries in your smoke detectors while you are changing your clocks.

Are there health issues with the changing of time?

For many of us, the return to standard time can be depressing. The day seems to fly by and it's dark before it's time to start thinking about dinner. But many doctors say the return to standard time can be healthy.

"Generally, it is always easier to stay up an hour later than to go to sleep an hour earlier, so most people have relatively little problem setting the clocks back in the fall," said Dr. Steven Feinsilver, director of the Center for Sleep Medicine at Mount Sinai School of Medicine in New York. "This is because our basic circadian rhythm (the 'body clock') actually seems to be programmed for a longer than 24 hour day. It runs a little slow."

"The circadian clock does not change to the social change," said chronobiology researcher Till Roenneberg of Ludwig Maximilans University in Munich, Germany. "During the winter, there is a beautiful tracking of dawn in human sleep behavior, which is completely and immediately interrupted when daylight saving time is introduced in the spring."

Roenneberg, lead researcher for a study of the effects of time shifts, said that humans' biological clocks are stronger than the clocks set by man-made laws.

"When you change clocks to daylight saving time, you don't change anything related to sun time," Roenneberg said. "This is one of those human arrogances, that we can do whatever we want as long as we are disciplined. We forget that there is a biological clock that is as old as living organisms, a clock that cannot be fooled. The pure social change of time cannot fool that clock."

Though individuals may see their biological clocks reset, and will get an "extra hour" of sleep or rest over the weekend, researchers say that the stress caused by time changes can be bad for the body.

Researchers in Sweden published a report in 2008 in the New England Journal of Medicine reporting that the number of heart attacks jumps during the period immediately following time changes, and that those vulnerable to sleep deprivation should be extra careful.

"More than 1.5 billion men and women are exposed to the transitions involved in daylight saving time: turning clocks forward by an hour in the spring and backward by an hour in the autumn," wrote Imre Janszky and Rickard Ljung, health and welfare researchers in Sweden. "These transitions can disrupt chronobiologic rhythms and influence the duration and quality of sleep, and the effect lasts for several days after the shifts."

Janszky and Ljung said that sleep deprivation can affect the cardiovascular system, leading the vulnerable to have heart problems in the days following the daylight savings time changes.

Source: ABCNews.go