German move to make most of daylight put our clocks on UK time
In 1908 the Liberal MP Robert Pearce introduced an innovative new Daylight Savings Bill to the House of Commons – designed to make the most of the summer months to boost productivity.
He quoted Ireland's best-known poet of the era, Sir Thomas Moore, who had written: "The best of all ways/To lengthen our days/Is to steal a few hours from the night."
The Bill stalled, the idea was sidelined, and then, when war came, the Germans did what the British had only talked about.
In April 1916, with the conflict bogged down in stalemate, Germany moved its clocks forward one hour in order to make the most of the daylight to conserve its reserves of coal and oil. Its allies the Austrians, and the neutral Dutch quickly followed suit, prompting the Westminster Parliament to rush through a bill putting Britain and Ireland on summer time from May 21.
This major change to the timekeeping habits of the British Isles provided Downing Street with the opportunity to tidy up the niggly time difference between the two islands while, some say, punishing the Irish for the recent Easter Rising.
Hundreds of miles west of London, the noonday sun passes over Dublin's Dunsink Observatory some 25 minutes after Greenwich on the outskirts of London.
The coming of the telegraph and the railways, with their timetables, meant that Irish time was standardised to Dublin mean time in 1880. At the start of the war Ireland set it clocks to GMT plus 25 minutes, which James Joyce referred to several times in 'Ulysses' as 'Dunsink Time'.
The Easter Rising of April 1916 coincided with the decision of the Westminster Parliament to rush through British summer time, and the need to mobilise troops against the rebels also highlighted the fact that having two time zones in one UK complicated communications.
Historians also believe that there was a symbolic element to banishing a separate Irish time zone, with the extension of GMT intended as a forceful reminder that Ireland was very much a part of the Union.
Dublin mean time was abolished on August 23, 1916.
See our dedicated World War 1 section here.
Irish Independent Supplement