The daylight-saving time change will force most of us to spring forward and advance our clocks one hour. This effectively moves an hour of daylight from the morning to the evening, giving us those long summer nights. But waking up 1 hour earlier may not be so easy, having lost an hour of precious sleep and perhaps driving to work in the dark. How time changes actually affect you depends on your own personal health, sleep habits, and lifestyle.
Setting our clocks back can wreak havoc on our internal clock which becomes out of sync or mismatched with our current day-night cycle. How well we adapt to this depends on several things. In general, "losing" an hour in the spring is more difficult to adjust to than "gaining" an hour in the fall. It is similar to airplane travel; traveling east we lose time. An "earlier" bedtime may cause difficulty falling asleep and increased wakefulness during the early part of the night. Going west, we fall asleep easily but may have a difficult time waking.
How long will it take you to adapt to time changes? Though a bit simplistic, a rule of thumb is that it takes about one day to adjust for each hour of time change. There is significant individual variation, however.
How will you feel during this transition? If you are getting seven to eight hours of sound sleep and go to bed a little early the night before, you may wake up feeling refreshed. If you are sleep-deprived already, getting by on six hours, you're probably in a bit of trouble, especially if you consume alcohol or caffeine close to bedtime. In this situation, you may well experience the decrements of performance, concentration, and memory common to sleep-deprived individuals, as well as fatigue and daytime sleepiness. What can you do to reset your internal clock to adapt more quickly to the time changes?
Sleep hygiene is a term used to describe those actions you can take to create sleep-friendly environments and enhance your chances of falling asleep, staying asleep, and sleeping soundly. Basic sleep hygiene includes reducing or eliminating caffeine and alcohol, exercising several hours before bedtime, creating calming rituals before bed to gradually relax yourself (taking a hot bath for example), and wearing ear plugs and eye masks, to name a few. Also important is going to bed and rising at the same time every day.
Interestingly, some studies show an overall reduction in traffic accidents and fatalities due to daylight-saving time changes. However, one study showed a significant increase in accident rates on the Monday following daylight-saving time. The study attributed sleepiness as a cause.