OHSU doctor talks daylight saving time's impact on biological clocks

PORTLAND, Ore. (KOIN) – With daylight saving time approaching on Sunday, the extra time for sunlight also means losing an hour of sleep.

This slight disruption in daylight can also disrupt the body's biological clock, explains Dr. Andrew McHill, occupational health scientist with Oregon Health & Science University.

“The reason it impacts our health so much is because each person has an internal biological clock in their brain that has to synchronize to the daily light-dark cycle every day. And just by losing an hour, shifting an hour over, it requires our brains to have to adjust that much more,” McHill said.

The time change comes as Florida Sen. Marco Rubio reintroduced the Sunshine Protection Act in early March after the Senate unanimously passed the bill in 2023 but failed in the House.

In Oregon, former Gov. Kate Brown signed a bill in 2019 that would allow the state to adopt daylight saving time year-round. However, the bill would need California and Washington to also switch to year-round daylight-saving time in addition to support from other lawmakers.

McHill says, from a scientific perspective, we should get rid of daylight saving time, noting, “the important thing would be to switch to standard time and not savings time because that will give us more light in the morning which will more easily synchronize our clock to match up with the light-dark cycle outside.”

The occupational health scientist says light is the most important signal for bodies to synchronize biological clocks.

“When you get light at night, it will actually make your clock be delayed, or later, which will then make you want to fall asleep later and wake up later, which is really hard with work and school things happening in the morning," McHill said.

He added “getting that morning light moves our clock earlier and will help us to wake up and be alert and be able to perform our duties for work or school.”

McHill recommends shifting sleep schedules a few minutes earlier to help adjust to the time change and to give yourself extra time to become more alert in the morning after the time springs forward.