DAYLIGHT SAVING TIME (history part 2)

Applying DST, did not begin until 1916 extensively, during the First World War, in order to relieve the hardships of war, saving coal and nighttime blackouts (hindering air strikes overnight).
It was applied by the German Empire, followed by the United Kingdom which was later joined by U.S.
After the war, most countries revoked the  DST, and those which remained did so by adapting the conditions for convenience (till today, because in some countries still do)
Although the controversies,  many countries have apply it (intermittently) since then.
Since 1974 the measure was fully implanted in the countries that currently follow it.

Countries in blue are currently using DST.
Countries in red, are those who have never used DST.
Countries in orange are not currently use daylight saving time, but have used it in the past.

map of the DST cointries followers taken from Wikipedia