Why do the clocks go forward and what impact does it have on your health?

By Emily Smith, PA

The clocks go forward on Sunday, marking the beginning of Irish Summer Time (IST).

This marks the end of Greenwich Mean Time (GMT) and will mean longer, lighter evenings from next week.

But besides losing an hour of sleep, the positive and negative impacts of daylight savings are hotly debated. But before we discuss why the clocks go forward, and the impacts on the body, why not let us know what you think about daylight saving time by taking our poll?

Now, here is everything you need to know about why and when the clocks go forward, as well as the impact on your body.

– When do the clocks go forward?

The clocks go forward at 1am on the last Sunday in March. This year that will be on March 30th.

IST – or daylight saving time (DST) – lasts until the final Sunday in October, when the clocks go back an hour.

– What does it mean for our sunlight?

Early risers will notice darker mornings immediately after the March change, while evenings will be lighter as the sun sets later.

As sunrise and sunset times continue to extend, parts of Ireland will see almost 19 hours of daylight by the summer solstice on June 21st.

– What are the benefits of the clocks going forward?

Dr Jeffrey Kelu, circadian rhythms expert at King’s College London, said there can be a number of arguments for DST.

He told the PA news agency: “I think there are some suggestions that there is less crime because more people are out there in the evening and it is harder to commit crimes.

“Also there are fewer traffic accidents because there is more light and people can see the traffic conditions more clearly. But there are conflicting studies.”

People are also in favour of clocks going back due to the increased daylight in the morning, which can lead to higher levels of productivity.

– What are the negatives?

Dr Kelu said: “The circadian clock regulates our physiology and metabolism, and we know that extreme cases such as shift working, causing circadian misalignment, will lead to increased risk in metabolic disorders such as obesity and diabetes.

“We believe that even for daylight savings time, the changing of the clock would be affecting health in some sense.

“The most acute effect would be the loss of an hour of sleep and also the inability to adapt to the new working schedule. So the scientists and communities, as well as the sleep experts, actually suggest removing daylight savings as a whole.”

– What can you do to prepare?

Dr Kelu suggests gradually changing the time you go to sleep in small increments in the days leading up to the clock change so it has less of an impact.

He said: “Because we cannot change the daylight saving time now, the thing is we can slowly prepare for it even though there’s not many days left.

“But we can slowly adjust to it by changing your clocks, for example, 15 minutes, 30 minutes, 45 minutes, until the hour changes.”

– Should daylight savings time be abolished?

Back in October 2024, BreakingNews asked its readers if they were fed up of the clocks going back.

US President Donald Trump posted in December that he wanted to scrap DST. His secretary of state Marco Rubio has also called the ritual of changing time twice a year “stupid”.