Changing the time twice a year was first established by the Summer Time Act of 1916, after a campaign by builder William Willett, so that evenings have more daylight and mornings have fewer daylight hours. It’s been changed a couple of times since then, notably during WW II when ‘Double’ summer time was introduced, 1941 to 1945 when Britain was GMT+2. Between 1968 and 1971 the clocks stayed at GMT+1 but statistics showed an increase in traffic accidents during the morning hours but a substantial decrease in the evening so UK reverted back to GMT/BST changes each year. Beginning at one o’clock, Greenwich mean time, in the morning of the last Sunday in March and ending at one o’clock, Greenwich mean time, in the morning of the last Sunday in October.
I hate it, it’s not natural, messes with my body clock, I’ve only just begun to get it into my head that in UK I can’t go shopping late evening, as most shops close after 17:00 hrs.