When the Clocks Fall Back
Why is my Child Struggling with Mood and Behavior after the End of Daylight Saving Time?
Daylight Savings Time (DST) ended this past weekend. Since becoming a parent, the end of DST has brought about two questions every year. First, when will I learn that the “extra hour” of sleep doesn’t actually exist when our young kids are still following their biological clock and now waking up at 5:30am instead of 6:30am? And second, what is going on with my kids’ moods this week? If you’ve been experiencing crankier mornings, more bedtime battles, and more emotional ups and downs this week, you’re not alone. While it may seem like a minor change, this extra little hour can have real biological and psychological effects on children’s developing brains.
A Sudden Shift in the Biological Clock
Our bodies run on an internal 24-hour rhythm known as the circadian clock, which regulates sleep, hunger cues, and alertness. This internal clock is set largely by light exposure.
When we “fall back,” mornings get lighter earlier and evenings get darker sooner. For adults this adjustment may seem small, but children’s circadian rhythms are more sensitive and slower to adapt. Their bodies don’t automatically understand that bedtime and wake-up time are suddenly one hour earlier.
This mismatch between the internal clock and the external world is called “circadian misalignment,” and it’s what causes many of the mood and behavior changes parents notice.
Early Mornings, Overtired Evenings
After the time change, many kids start waking up too early because their internal clocks still think it’s time to get up. We are slowly adjusting over here, but the first few days of the week were rough with very early starts to our days! At the same time, earlier darkness in the evening can trick the brain into releasing the “sleep hormone” melatonin sooner than usual. That disrupted sleep pattern can lead to:
Irritability and crankiness, especially in the late afternoon
Difficulty concentrating at school
Emotional outbursts over small frustrations
Increased clinginess or anxiety, especially in younger children
Mood Regulation and Brain Chemistry
Sleep and mood are tightly connected, especially in children whose brains are still developing the ability to regulate emotions. When DST ends, several key systems are affected:
Melatonin production shifts earlier due to darker evenings, confusing the body’s natural rhythm.
Serotonin, a neurotransmitter linked to mood and calmness, can dip with reduced daylight exposure, contributing to sadness or low motivation.
Cortisol, which helps with alertness in the morning, may peak too early or too late, making kids groggy during the day.
For some children, especially those prone to anxiety or seasonal affective symptoms, this change in light and hormone timing can trigger low mood, irritability, or increased emotional sensitivity.
Why Evenings Feel Harder
Once the clocks shift, darkness falls during late afternoon, right around the time kids are finishing school or heading home. This can impact behavior and mood in several ways:
Reduced outdoor playtime: Less daylight after school means fewer chances for physical activity - a proven mood booster.
Changes in family rhythm: Dinner, homework, and bedtime now happen in darkness, which can make evenings feel longer or more stressful.
Emotional fatigue: The brain interprets early darkness as a cue to wind down, but social schedules often demand alertness, creating internal conflict and irritability.
In short, earlier sunsets can make the day feel shorter while the evening routines can drag out and feel more emotionally charged.
Strategies to Help Support the DST Adjustment
The good news: children’s bodies can adapt, especially with gentle guidance. These strategies can ease the transition when DST ends:
Increase your sunlight exposure: Open the blinds or go outside shortly after waking. Natural light helps re-anchor the circadian clock to the new time.
Adjust the bedtime routine gradually: Shift bedtime and wake-up time by 10–15 minutes for a few days before and after the clock change (psst: this strategy works in the Spring when we need to adjust to DST all over again).
Prioritize physical activity: If possible, encourage outdoor play in the afternoon while it’s still light. This improves sleep quality and boosts serotonin.
Keep bedtime consistent and calm: Use the same routines (like pajamas, brush teeth, story, lights out) to cue the brain for sleep, even if darkness falls earlier (or lighter when we are back in DST next spring!).
Limit evening screens: This can be a tough one, especially when the kids aren’t able to be outside playing because it’s now getting dark earlier. That said, blue light delays melatonin production, making it harder for kids to fall asleep at bedtime. Cutting down on evening screen time even by a few minutes each night can make a big difference.
Final Thoughts
If you are noticing more tears, tantrums, or defiance in the weeks after the time change, you aren’t alone! Try to remind yourself that these behaviors aren’t intentional - they’re biological signs of dysregulation. The earlier darkness, hormonal shifts, and subtle sleep changes can all affect mood, focus, and emotional resilience.
Responding with patience, empathy, and predictable structure helps children regain their sense of stability while their bodies adjust. Take a deep breath and be gentle with yourself, too. We need to provide ourselves with that same patience, empathy, and predictability as we continue to ease into the darker afternoons.