BioClock in the spotlight as we switch to daylight saving time

As we transition into daylight saving time once again, the biological clock takes center stage in public discussion. Several BioClock researchers recently had the opportunity to share their expertise in national media, offering insights into the historical roots of daylight saving time, its societal impact, and its consequences for our biological clock.

The History of Daylight Saving Time and Why It’s Time for a Change

Together with Universiteit van Nederland, Maaike van der Rhee explores how daylight saving time first started and became embedded in Dutch society. Although originally introduced for economic and energy-saving reasons, modern research increasingly shows that these benefits are limited. They are far outweighed by negative biological effects.

In the UniNL video, she explains why a transition to permanent standard time—or even natural time (the time zone that most closely aligns with the sun)—fits better with our biological rhythms. Permanent standard time ensures that our internal clock stays synchronized with the natural light-dark cycle, supporting healthier sleep, improved alertness, and more stable daily functioning, as well as a lowered risk of several health issues.

Does healthcare demand change with the clock?

In a recent article by Nederlands Tijdschrift voor Geneeskunde (NTvG), Laura Kervezee comments on a British study investigating fluctuations in healthcare demand around the clock change.

This study found that healthcare use decreased after the switch back to winter (standard) time, which aligns better with the sun. Especially anxiety disorders, depression, sleep disorders, and acute cardiovascular events saw a decline.

Laura explains that as we near the end of the summertime period, the sun rises progressively later and we get exposed to less morning light than we would if standard time were in place year-round. This lack of morning light is linked to negative health effects, which seem to be reduced after the clock is changed back to standard time and exposure to morning light increases.

Laura also shares her expertise on the biological clock on local radio station Sleutelstad FM , where she highlighted the physiological consequences of what she describes as a forced one-hour jet lag that persists all summer long. From disrupted sleep to increased health risks, the negative effects are clear. Therefore, Laura calls for ending the annual switch to daylight saving time and adopting the time zone that that best fits the geographical location of our country.

The immune systems clock

The biological clock influences far more than just sleep. In a new video with NTRWetenschap, BioClock researcher Anneke Kastelein explains how our immune system follows the circadian rhythm. The video focusses on the effectiveness of vaccinations: “Beter in the morning,” explains Anneke. Now that daylight savings time has started again, and summer is on its way, travel vaccines might be on your planning. Anneke’s advise? Get them in the morning to maximize their effect.

BioClock is proud to be an established authority on daylight savings time and we’re happy so many of our researchers got to share their expertise with the world.