Greenwich Mean Time - Discrepancies Between Legal GMT and Geographical GMT

Discrepancies Between Legal GMT and Geographical GMT

Since legal, political, and economic criteria (in addition to purely physical or geographical criteria) are used in the drawing of time zones, it follows that actual time zones do not precisely adhere to meridian lines. The 'GMT' time zone, were it drawn by purely geographical terms, would consist of exactly the area between meridians 7°30'W and 7°30'E. As a result, there are European locales that despite lying in an area with a 'physical' UTC time, actually use another time zone (UTC+1 in particular); coversely, there are European areas that use UTC, even though their 'physical' time zone is UTC−1 (e.g., most of Portugal), or even UTC−2 (the westernmost part of Iceland). Actually, because the UTC time zone in Europe is 'shifted' to the west, Lowestoft in Suffolk, East Anglia, England at only 1°45'E is the easternmost settlement in Europe in which UTC is applied. Following is a list of the 'incongruencies':

Countries (or parts thereof) west of 22°30'W ("physical" UTC−2) that use UTC

• The westernmost part of Iceland, incl. the northwest peninsula and its main town of Ísafjörður, which is west of 22°30'W, uses UTC. Bjargtangar, Iceland is the westernmost point in which UTC is applied.

Countries (or parts thereof) west of 7°30'W ("physical" UTC−1) that use UTC

• Canary Islands (Spain)
• Most of Portugal, incl. Lisbon, Porto, Braga, Aveiro, and Coimbra. (Only the easternmost part, incl. cities such as Bragança and Guarda, lies east of 7°30'W.). Portugal has since the Treaty of Windsor (1386, world's oldest diplomatic alliance) always had close ties to Britain, which possibly explains its choice of UTC. The Madeira Islands, even further to the west, also employ UTC. A more likely explanation is that during the mid-1970s, when Portugal was on Central European Time all year round, it did not begin to get light in Lisbon in winter until 8.30 A.M.
• Western part of Ireland, incl. the cities of Cork, Limerick, and Galway. If uninhabited islands or rocks, or both, are to be taken into account then Rockall (Disputed island), at 13°41'W, should also be included.
• Westernmost tip of Northern Ireland, incl. the capital of County Fermanagh, Enniskillen
• Extreme westerly portion of the Outer Hebrides, west of Scotland; for instance, Vatersay, an inhabited island in the Outer Hebrides and the westernmost settlement in the whole of Great Britain, lies at 7°54'W. If uninhabited islands or rocks, or both, are to be taken into account then St Kilda, west of the Outer Hebrides, at 8°58'W, and Rockall (Disputed island), at 13°41'W, should also be included.
• Westernmost island of the Faroe Islands (autonomous region of the Danish Kingdom), Mykines
• Iceland, including Reykjavík

Countries (mostly) between meridians 7°30'W and 7°30'E ("physical" UTC) that use UTC+1

• Spain (except for the Canary Islands which use UTC). Parts of Galicia in fact lie west of 7°30'W ('physical' UTC−1), whereas there is no Spanish territory east of 7°30'E ('physical' UTC+1). Spain's time is the direct result of Franco's Presidential Order (published in Boletín Oficial del Estado of 8 March 1940) abandoning Greenwich UTC time in favour of UTC+1 effective 23:00 16 March 1940. This is indeed an excellent example of the aforementioned political criteria used in the drawing of time zones: the time change was passed "in consideration of the convenience from the national time marching in step according to that of other European countries". The Presidential Order (most likely enacted to be in synchrony with Germany and Italy, with which the Franco regime was unofficially allied) included in its 5th article a provision for its future phase out, which never took place. Due to this political decision Spain is two hours ahead of its local mean time during the summer (one hour ahead in winter), which possibly explains the notoriously late schedule for which the country is known. However, in Portugal, which is a mere one hour behind Spain, the timetable is quite different.
• Most of France, including the cities of Paris, Marseilles and Lyon. Only small parts of Alsace, Lorraine and Provence are east of 7°30'E ("physical" UTC+1).
• Belgium
• Netherlands
• Luxembourg