Atlantic/Jan_Mayen

Although I could not find it explicitly, it seems that Jan Mayen and Svalbard have been using the same time as Norway at least since the time they were declared as parts of Norway. Svalbard was declared as a part of Norway by law of 1925-07-17 no 11, section 4 and Jan Mayen by law of 1930-02-27 no 2, section 2. (From < and < The law/regulation for normal/standard time in Norway is from 1894-06-29 no 1 (came into operation on 1895-01-01) and Svalbard/Jan Mayen seem to be a part of this law since 1925/1930. (From < I have not been able to find if Jan Mayen used a different time zone (e.g. -0100) before 1930. Jan Mayen has only been "inhabited" since 1921 by Norwegian meteorologists and maybe used the same time as Norway ever since 1921. Svalbard (Arctic/Longyearbyen) has been inhabited since before 1895, and therefore probably changed the local time somewhere between 1895 and 1925 (inclusive).

Actually, Jan Mayen was never occupied by Germany during World War II, so it must have diverged from Oslo time during the war, as Oslo was keeping Berlin time. < says that the meteorologists burned down their station in 1940 and left the island, but returned in 1941 with a small Norwegian garrison and continued operations despite frequent air attacks from Germans. In 1943 the Americans established a radiolocating station on the island, called "Atlantic City". Possibly the UT offset changed during the war, but I think it unlikely that Jan Mayen used German daylight-saving rules. Svalbard is more complicated, as it was raided in August 1941 by an Allied party that evacuated the civilian population to England (says < The Svalbard FAQ < says that the Germans were expelled on 1942-05-14. However, small parties of Germans did return, and according to Wilhelm Dege's book "War North of 80" (1954) the German armed forces at the Svalbard weather station code-named Haudegen did not surrender to the Allies until September 1945. All these events predate our cutoff date of 1970, so use Europe/Berlin for these regions.

The tzdata source notes: 00 MEZ, not the 2:00 MEZ given in Shanks & Pottenger. Go with the PTB.