UK tested year-round British Standard Time

For three years, from October 27, 1968, to October 31, 1971, the United Kingdom kept British Standard Time (BST), which is GMT+1, throughout the year instead of switching back to Greenwich Mean Time (GMT) in winter.

Accident reduction estimated

The Transport and Road Research Laboratory (TRRL) estimated that keeping BST during those winters may have reduced fatalities and serious injuries by about 2,700, though it stressed these numbers were approximate and not exact.

Regional impact varied

The shift in time affected different regions differently, with northern Scotland experiencing an increase in accident statistics, highlighting regional differences in how the time change was experienced.

Experiment based on surveys

The experiment followed surveys in the late 1950s and early 1960s that suggested a slight preference for keeping BST year-round, leading the Harold Wilson government to implement the trial in 1968.

Historical context of DST

Daylight saving time had been in place since a 1916 law that moved clocks forward by one hour from May 21 to October 1 to support the war effort, and the experiment started shortly after a 1967 law that restricted alcohol consumption in road traffic.

Parliament rejected BST

In December 1970, the Commons rejected BST by a vote of 366 to 81, deciding to return to GMT on October 31, 1971, with more than 30 MPs expected to speak on the issue, reflecting the divided opinions.

Public and sectoral opinions

Surveys showed the public was split, with 50% wanting to stay on BST during winter and 41% wanting to return to GMT, while business sectors supported BST for alignment with Western Europe, and workers like postmen opposed it due to long dark mornings.

Regional opposition highlighted

Northern Scotland strongly opposed BST, with 61% of people wanting to return to GMT, and one MP noted that in December it was not until 10:15 AM that daylight was visible, emphasizing the region's concerns about darkness.

Reanalysis confirmed earlier findings

A 1989 reanalysis by TRRL, which considered the impact of the 1967 road traffic alcohol law, found results broadly consistent with the earlier estimates, but the Commons vote in 1970 ended the experiment, returning the UK to GMT in 1971.

Legacy in ongoing debate

The episode remains part of the British debate on time zones and daylight saving, with the House of Commons library referencing it in a note on the Daylight Saving Bill 2010-11, showing its lasting influence on policy discussions.