The debate over changing the clocks has returned to the fore, with proponents arguing that permanent Daylight Saving Time could help ease the energy crisis. In the UK, daily energy demand peaks between 5pm and 7pm, and demand in winter starts to rise sharply just before 4pm. Extra daylight in the afternoon and evening would mean people put their lights and heating on later, while darker mornings would have a negligible impact on energy since households tend to use lights and heating on winter mornings anyway.
According to 2022 research from Aoife Foley of Queen's University Belfast, sticking to BST could save households between £1.2 billion and £2.3 billion a year, while the Republic of Ireland could cut its carbon emissions by 3.5% due to the decrease in residential usage.
The UK has tried permanent summer time before. During the Second World War, the clocks were moved forward by an hour all year-round, and the experiment was repeated in 1947 because of severe fuel shortages. In the late 1960s the UK adopted permanent BST for three years before returning to the spring-forward fall-back system, partly because of the effect in Scotland, where year-round BST means dark mornings in winter.
In the US, the House of Representatives passed the Sunshine Protection Act in July, which – if passed by the Senate – would move the whole of the US to permanent Daylight Saving Time. President Donald Trump strongly backs the legislation. However, critics argue that permanent standard time – GMT – more closely aligns with the body's circadian rhythms. Beth Ann Malow wrote on The Conversation that morning light is essential for setting the body's natural rhythms, and that extending evening light delays the release of melatonin, interfering with sleep.