The clocks go forward on the last Sunday of March, at one in the morning, when 1 am becomes 2 am and that hour simply does not exist. British Summer Time then runs until the last Sunday of October. It is the change people notice most, because it moves an hour of daylight into the evening overnight and takes an hour of sleep to pay for it.
March closes the first calendar quarter of 2030 on the 31st and takes the tax year to within days of its own end. That mismatch of five days between the two year ends is a genuine British peculiarity, inherited from the switch to the Gregorian calendar in the eighteenth century and never tidied up since.
The turn from March into April takes the country from the last of the winter routine into the first proper holiday season of the year. March 2030 hands over a month with one regional bank holiday to one that commonly carries two national ones, along with a fortnight of school holidays.