{"id":58405,"date":"2026-10-22T09:09:08","date_gmt":"2026-10-22T09:09:08","guid":{"rendered":"https:\/\/filtrarte.com\/?p=58405"},"modified":"2026-10-22T09:09:08","modified_gmt":"2026-10-22T09:09:08","slug":"clocks-go-back","status":"publish","type":"post","link":"https:\/\/filtrarte.com\/en\/clocks-go-back\/","title":{"rendered":"Clocks go back: how to protect your sleep when switching to winter time"},"content":{"rendered":"\n

Overnight from Saturday to Sunday, 25 October 2026, the clocks go back one hour in mainland Portugal and Madeira: 2:00 a.m. becomes 1:00 a.m. In the Azores, the clocks go back<\/strong> at 1:00 a.m., which becomes midnight. In the UK, the clocks also go back that night, at 2:00 a.m., which becomes 1:00 a.m. This is the switch to winter time<\/strong>, which takes place on the same day in every Member State of the European Union.<\/p>\n\n\n\n

Gaining an hour on Sunday night seems like an advantage. Even so, many people spend the following days waking up before the alarm and feeling hungry at odd times. They also fight drowsiness in the late afternoon, when it gets dark earlier. The reason lies in the body\u2019s internal clock, which does not reset as quickly as a mobile phone.<\/p>\n\n\n\n

This guide explains what happens to the body when the clocks change and who tends to feel the difference most. It also covers the changes to schedules, light and the bedroom environment that make the week of adjustment easier.<\/p>\n\n\n\n

Why the clocks go back in Europe<\/h2>\n\n\n\n

The clocks go back and forward because European legislation harmonises summer time arrangements in all Member States, with common start and end dates.<\/p>\n\n\n\n

Under Directive 2000\/84\/EC, summer time begins on the last Sunday of March and ends on the last Sunday of October. In Portugal, these arrangements are transposed by Portuguese Decree-Law No. 17\/96. The dates are the same throughout the Union, so the change on 25 October happens at the same moment in Lisbon, Madrid, Paris and Athens. Each country, however, keeps its own time zone.<\/p>\n\n\n\n

Ending the seasonal clock changes has been under discussion for several years. According to the Council of the European Union, the European Commission presented a proposal in September 2018 to end the twice-yearly change. The European Parliament adopted its position in March 2019. The Council, however, has not yet reached an agreement, no final decision has been taken and there is no set timetable. Until then, the alternation between summer time and winter time continues.<\/p>\n\n\n\n

What happens to the body when the clocks change<\/h2>\n\n\n\n

When the clocks change, social time shifts immediately, but the biological clock needs a few days to catch up with the new routine.<\/p>\n\n\n\n

The circadian rhythm<\/strong> refers to the physical, mental and behavioural changes the body goes through over a cycle of around 24 hours. This is how the US National Institute of General Medical Sciences describes it. This rhythm influences sleep, hormone release, appetite, digestion and body temperature.<\/p>\n\n\n\n

The central clock, light and melatonin<\/h3>\n\n\n\n

Everything is coordinated by a central clock in the brain, formed by a group of nerve cells called the suprachiasmatic nucleus. The same institution explains that the alternation between light and darkness is the cue with the greatest influence on this clock. Even so, diet, physical activity, stress, the social environment and temperature also play a part.<\/p>\n\n\n\n

It is this clock that regulates the production of melatonin<\/strong> according to the light picked up by the eyes. At the end of the day, fading light leads the brain to produce more melatonin, the hormone associated with sleepiness. When the clocks change, the hours of light and darkness shift in relation to the wall clock, and the body needs time to realign these signals.<\/p>\n\n\n\n

One hour\u2019s difference, several effects on daily life<\/h3>\n\n\n\n

With the switch to winter time, the mismatch is one hour. For someone who usually wakes at 7:00 a.m., the body carries on for a few days as if it were 8:00 a.m. Hence waking at around 6:00 a.m. on the new time, feeling hungry earlier for lunch and tiredness setting in earlier in the evening.<\/p>\n\n\n\n

Why the October change is usually gentler<\/h3>\n\n\n\n

The American Academy of Sleep Medicine supports ending seasonal clock changes and adopting permanent standard time. In its view, summer time is less aligned with human circadian biology. The same organisation links the most significant acute risks to the spring change, when an hour is lost.<\/p>\n\n\n\n

A modelling study published in 2024 in the journal Scientific Reports points the same way. In a scenario of moderate indoor light, it estimated around 10 days of adjustment after the autumn change, compared with around 13 and a half days after the spring change. The October adjustment therefore tends to be gentler, but it is not immediate.<\/p>\n\n\n\n

Who feels it most when the clocks go back<\/h2>\n\n\n\n

Not everyone feels it in the same way when the clocks go back, and some profiles tend to need more time to adjust.<\/p>\n\n\n\n