Daylight Saving and Your Body Clock: Protecting Sleep (and Your CPAP Routine)

This Sunday, most of Australia resets the clocks. On 5 October, New South Wales, Victoria, South Australia, Tasmania and the ACT spring forward into daylight saving — losing an hour in the process (Queensland, WA and the NT, as ever, sit it out). If your sleep feels slightly off in the days that follow, you won't be imagining it: even a one-hour shift nudges your body clock out of step. For anyone managing sleep apnea, that's worth taking seriously — because protecting your routine through the change is also a chance to tidy up the habits that make your therapy work.

What happened

Daylight saving disrupts your circadian rhythm — the internal body clock set largely by when you're exposed to natural light. Push the clock forward and, for a while, your body is being asked to sleep and wake before it's ready. Most people adjust within days, but the transition is real, and sleep scientists have grown increasingly wary of the costs of shifting the clocks at all.

The short-term effects can be surprisingly sharp, particularly after the spring-forward lost hour. Research has linked the days immediately after the change to a measurable uptick in heart attacks and strokes — a Finnish study, for instance, found roughly an 8% rise in ischaemic strokes in the two days afterward. The exact mechanism isn't proven, but the leading explanation is simple: circadian disruption and a dose of lost sleep. It's a reminder that an hour isn't trivial to a body that runs on rhythm.

Much of this evidence is observational — researchers believe the harm is circadian, driven by disrupted light exposure and lost sleep, rather than definitively proven.

Why it matters

For people with obstructive sleep apnea, sleep is already the thing under pressure. A sudden schedule shift can fragment it further — and, just as importantly, a disrupted routine is when good habits slip. Skip the mask on a few odd-feeling nights and the benefits of therapy start to unravel, right when your body most needs the support.

The flip side is the opportunity. A clock change is a natural prompt to reset: lock in a consistent sleep schedule and consistent CPAP use, and you're strengthening the two things that quietly determine how well your therapy works.

What this means for you

Whether you're bracing for this weekend's lost hour, or looking ahead to the wind-back in April (daylight saving ends on the first Sunday), here's how to protect your sleep and your therapy through any change:

Shift gradually. Around a clock change, move your bedtime by 15–20 minutes over several nights rather than all at once. Nudge mealtimes the same way — they're body-clock cues too.
Chase morning light. Getting outside into bright daylight early helps reset your body clock faster than almost anything else.
Keep CPAP on every night — including the rough ones. The disrupted nights are exactly when consistency matters most. Don't let one off night become an off week.
Hold one schedule, weekends included. A steady sleep and wake time is what re-anchors your rhythm; sleeping in undoes the progress.
Go easy on caffeine, alcohol and screens in the hours before bed while you readjust, and keep any naps short (15–20 minutes) and early in the day.
Mind drowsy driving for the week or so after a change — adjustment takes longer than most people expect.

The bottom line

You can't opt out of the clocks changing, but you can control how smoothly you ride the transition — and for anyone on CPAP, that means guarding a steady routine and not missing a night on the machine. Treat each time change as a cue to reset your sleep habits for the better rather than let it throw them. If a fresh mask or a more comfortable setup would help you stay consistent, that's where we come in.

Sources:
https://www.sleepfoundation.org/circadian-rhythm/daylight-saving-time
https://www.sleephealthfoundation.org.au/