When Daylight Saving Time Ends

Get ready to gain an hour of sleep. The “fall back” time change happens on Sunday, November 5, 2023 in most of the U.S. How the time changes actually affect you depends on your own personal health, sleep habits, and lifestyle.

Moving our clocks in either direction changes the principal time cue — light — for setting and resetting our 24-hour natural cycle, or circadian rhythm. In doing so, our internal clock 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 harder to adjust to than “gaining” an hour in the fall. It’s similar to airplane travel; traveling east we lose time. An “earlier” bedtime may cause trouble 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 change? Though a bit simplistic, a rule of thumb is that it takes about one day to adjust for each hour of time change. But this can vary significantly among people. 

What can you do to reset your internal clock to adapt more quickly to the time changes? Your circadian rhythm is internally generated but is influenced by your environment, behavior, and medications. 

•  Light is the principal environmental cue. Light suppresses the release of the sleep-inducing substance melatonin. So it’s important to expose yourself to the light during the waking hours as much as possible — and to avoid bright light when it is dark outside. For example, if you get up at night to go to the bathroom, do not turn on the light. (A night light is OK.)  Interestingly, specifically timed light therapy may either advance or delay your sleep cycle, depending on when you use it.
• Sleep hygiene is a term used to describe things you can do 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. It’s also important to go to bed and rise at the same time every day. As for food, although there is no evidence that certain diets will actually influence your circadian rhythm, carbohydrates tend to make it easier to fall sleep.
• It’s unlikely that medications would be needed for a simple one-hour time change of the clock. But in certain circumstances, like traveling across multiple time zones, your doctor may consider prescribing a short course of sleep or anti-anxiety medications. Some of these medications have the potential for  addiction and can negatively affect the quality of sleep, so they should only be used under the direct guidance of a doctor or sleep specialist.

Take care when you’re driving in the dark, and especially if you’re tired.