Daylight Saving Prep: Protecting Your Cycle Through Time Changes

Time changes disrupt circadian rhythms - the internal clocks that regulate sleep, hormone secretion, and overall well-being. When Daylight Saving Time ends, these disruptions can throw your menstrual cycle and productivity off balance. By syncing your routine to your cycle and adjusting your light exposure, you can stay grounded, energized, and one step ahead of the shift.

You know the drill: clocks fall back, sunsets come too soon, and your entire rhythm feels... off.

But if you're someone with a menstrual cycle, the end of Daylight Saving Time doesn't just mess with your calendar — it can derail your energy, your sleep, and (yep) your hormones. In fact, your internal timing is so interwoven with environmental light that even a one-hour shift can ripple through your entire system.

The good news? This isn't something you have to just "power through." With a little preparation and some cycle-aware strategies, you can protect your hormones, maintain your productivity, and sail through the time change while everyone else is dragging.

So let's understand what's happening, why it matters, and how — with a little planning — you can sidestep the chaos entirely.

How Time Changes Affect Your Cycle

Circadian rhythms are the 24-hour cycles that control your sleep-wake timing, hormone release, metabolism, body temperature, and even your immune function. These rhythms are regulated primarily by light exposure, especially morning sunlight, which anchors your body clock and tells your brain when it's time to be alert or wind down.

When clocks ‘fall back’ over the coming weeks: 

- Sunrise hits earlier, and many of us miss that critical morning light if we're still inside getting ready for work.

- Evening light disappears faster, which can trick your body into thinking it's bedtime at 5pm — long before you're ready to sleep.

- Melatonin (the sleep hormone) kicks in too soon, potentially making you groggy earlier than usual.

- Cortisol (your natural "get-up-and-go" hormone) might spike too early or too late, further unbalancing your day and making mornings feel sluggish or evenings feel wired.

Light changes combined with the temperature shifts of the move towards winter can play havoc with your productivity and energy.  But there are proactive steps you can take to keep yourself strong.  

What does this have to do with your menstrual cycle? A lot.

The ovarian hormones estrogen and progesterone don't operate in isolation — they're tightly linked to your circadian rhythm. Research from Nature and  Avogel shows that fluctuations in light exposure can disrupt the hormonal signaling that governs ovulation, PMS symptoms, and even cycle length.

Here's what that looks like in real life:

- Delayed ovulation: If your circadian rhythm is off, the luteinizing hormone (LH) surge that triggers ovulation can be delayed or weakened.

- Worsening PMS: Poor sleep and late-day light exposure can amplify irritability, anxiety, and physical symptoms during your luteal phase.

- Cycle length changes: Some women report shorter or longer cycles after time changes, especially if sleep is disrupted for multiple nights in a row.

- More fatigue: Estrogen and progesterone affect how well you sleep. When sleep is disrupted, those hormones can't do their job properly, leaving you exhausted.

Result: More fatigue during your luteal phase, brain fog during meetings, worsening PMS, or even cycle length irregularities that throw off your entire month.

Even more annoyingly? Your body can take up to 7 days to re-establish a stable rhythm after a time change 

That's a full week of feeling "off" — unless you prepare ahead.

Preparing for "Fall Back" by Cycle Phase

There's no one-size-fits-all approach to handling DST. Your menstrual phase can significantly impact how sensitive you are to circadian shifts and how well you adapt. Here's a breakdown of what to prioritize based on where you're at when the clocks change:

Menstrual Phase (Days 1–5)

What You Might Experience:  

Lower baseline energy, more disrupted sleep due to cramps or discomfort, heightened sensitivity to stress.

What to Do:  

- Prioritize extra rest and give yourself permission to slow down.

- Reduce demanding social or cognitive tasks if possible.

- Stick to a consistent bedtime even if you're tempted to "use" that extra hour.

- Use heat therapy (heating pads, warm baths) to support relaxation and sleep quality.

- Avoid alcohol and caffeine, which can further disrupt sleep during this phase.

Why it matters:  

Your body is already in a natural rest-and-reset mode. Fighting that by pushing too hard will only compound the effects of the time change.

Follicular Phase (Days 6–14)

What You Might Experience:  

Rising energy levels, better resilience to stress, improved sleep quality as estrogen increases.

What to Do:  

- Use this phase to re-establish morning routines and lock in your new wake-up time.

- Get 10–20 minutes of morning sunlight as early as possible to anchor your circadian rhythm.

- Start new habits or projects — your brain is primed for adaptation right now.

- Increase physical activity in the morning to help regulate your body clock

Why it matters:  

This is your biological bounce-back phase. Your body is naturally more adaptable, so use that to your advantage.

Ovulatory Phase (Days 15–17)

What You Might Experience:  

Peak energy, stable mood, high confidence, less sensitivity to sleep disruptions.

What to Do:  

- Embrace the earlier start times and use your peak cognitive performance for important work.

- Schedule demanding meetings, presentations, or social events during this window.

- Leverage your natural resilience — you'll likely adjust faster than during other phases.

Why it matters:  

Your hormones are at their most balanced. If the time change falls here, you're in the best possible position to handle it smoothly.

Luteal Phase (Days 18–28)

What You Might Experience:  

Increased sensitivity to stress, blood sugar fluctuations, potential mood swings, difficulty falling asleep or staying asleep.

What to Do:  

- Maintain strict hydration and eat balanced meals to stabilize blood sugar.

- Limit screen time in the evening — blue light hits harder during this phase.

- Use magnesium glycinate supplements (if approved by your healthcare provider) to support relaxation.

- Build in buffer time between tasks to avoid feeling overwhelmed.

- Practice breathwork or gentle yoga before bed to calm your nervous system.

Why it matters:  

This is when your body is most vulnerable to circadian disruption. Extra care now prevents a cascade of PMS symptoms later

By working with your body, rather than against it, you can use cycle syncing to find a more productive version of yourself. 

Light Management Strategies That Actually Work

Light is the most powerful tool you have to reset your circadian rhythm and protect your hormones. Here's how to use it strategically around the time change:

1. Front-Load Morning Sunlight

Get outside within 30 minutes of waking up, ideally before 9am. Even on cloudy days, natural light is 10–100x brighter than indoor lighting and signals your brain that it's time to be alert.

How to do it:

- Take your coffee or breakfast outside

- Walk around the block before starting work

- Stand by an open window while you get ready

- If you're a morning exerciser, move your workout outdoors

Sleepfoundation.org shines a light on prioritizing daylight exposure as a key step to adjusting to the new times.

2. Reduce Blue Light in the Evenings

After sunset (which will now come frustratingly early), your body needs darkness to produce melatonin properly. Blue light from screens tricks your brain into thinking it's still daytime, delaying sleep and disrupting hormone cycles.

How to do it:

- Install blue-light filters on all devices (f.lux, Night Shift, etc.)

- Wear amber-tinted glasses after 7pm

- Dim overhead lights and use warm-toned lamps instead

- Avoid scrolling in bed — read a physical book or journal instead

3. Be Strategic About Naps

That "extra hour" from fall-back can tempt you to nap longer or later in the day. Resist. Napping after 3pm can interfere with nighttime sleep and make it harder to adjust.

If you must nap:

- Keep it to 20–30 minutes max

- Nap before 2pm

- Use a sleep mask to block light

4. Stabilize Your Meal Times

Your digestive system also follows a circadian rhythm. Eating at consistent times helps anchor your body clock and supports stable blood sugar — which directly impacts sleep quality and hormone balance.

What to do:

- Don't skip breakfast, even if you're not hungry right away

- Avoid large meals within 3 hours of bedtime

- Limit sugar and refined carbs at night to prevent glucose crashes that disrupt sleep

- Consider a small protein-rich snack (like Greek yogurt or nuts) if you're prone to waking up hungry

5. Adjust Bedtime Gradually

Starting one week before the time change, shift your bedtime earlier by 10–15 minutes every couple of nights. By the time the clocks officially change, your body will already be adapted.

Pro tip:  

Set a bedtime alarm — not just a wake-up alarm. Most of us are terrible at going to bed on time without a reminder.

6. Use Light Therapy If Needed

If you struggle with Seasonal Affective Disorder (SAD) or live in a region with very short winter days, consider investing in a light therapy lamp (10,000 lux). Use it for 20–30 minutes in the morning while you have breakfast or check emails.

This can be especially helpful during your luteal and menstrual phases when energy is naturally lower. 

Final Thought: Your Clock Changed. Your Body Didn't.

Just because the world decides to "fall back" doesn't mean your biology reprograms overnight.

Your circadian rhythm is a finely tuned system that regulates everything from how you sleep to when — and how well — your hormones function. When you ignore those rhythms and just "push through," you're setting yourself up for exhaustion, hormonal chaos, and a month of playing catch-up.

But when you work with your cycle? When you prepare proactively and give your body what it needs? You don't just survive the time change — you thrive through it.

This November, don't let Daylight Saving Time steal your energy, disrupt your cycle, or derail your goals. Protect your rhythm. Honor your phase. And let Phase do the heavy lifting.

Because your hormones are a superpower. And it's time to start treating them like one.

✨ Track your cycle. Tune into your rhythm. Thrive with Phase.

Download Phase now: https://www.phaseapp.io/