[TG626]

Here's another wrinkle

DST was first adopted to replace artificial lighting so they could save fuel for the war effort in Germany during World War I at 11:00pm (23:00) on April 30, 1916. It was quickly followed by Britain and many countries from both sides, including the United States. Many countries reverted back to standard time post-World War I, and it wasn’t until the next World War that DST would make its return to many countries in order to save vital energy resources for the war.

President Franklin D. Roosevelt instituted year-round DST in the United States, called “War Time” during World War II from February 9, 1942 to September 30, 1945. The law was enforced 40 days after the bombing of Pearl Harbor and during this time, time zones were called “Eastern War Time”, “Central War Time”, and “Pacific War Time”. After the surrender of Japan in mid-August 1945, the time zones were relabeled “Peace Time”.

Daylight saving was first recognized as an energy saving aspect during World War II when Double Summer Time was applied in Britain which moved the clocks two hours ahead of GMT during the summer and one hour ahead of GMT during the winter.