[tz] Official definition and origin of the term "Central European Time"

Even Scharning tzdb at time.is
Fri Oct 23 18:52:18 UTC 2015

Is there an official definition of the term "Central European Time" 
(CET), specifically which UTC offset(s) it refers to?

If there is no official definition, where did the term originate from?

I asked the information desk at the EU (Europe Direct) to help me find 
links to relevant legislature, but their reply was that term CET is "not 
regulated at a EU level, but internationally".

All credible sources I have found, say that CET is a constant UTC+1. 
The closest thing I have found to an authoritative document, is the 
German Time Act from 1978. It says: "Legal time is Central European 
Time. It is defined as Coordinated Universal Time plus one hour." There 
is no reference to the origin of this definition, and no information of 
whether anyone other than the Germans agree on this definition.

On the EU's web pages (for instance 
http://europa.eu/contact/index_en.htm) times are usually given in CET, 
not CEST (Central European Summer Time), even though daylight saving 
time is currently observed. Google gives a few hundred thousand results 
for CET on europa.eu, and numerous of these results are hits on dates in 
the daylight saving time period.

I think it makes more sense to define CET as alternating between UTC+1 
(standard time) and UTC+2 (when DST is observed). (See 
http://time.is/CET for a more elaborate definition.)

This is in line with for instance the US time zones Pacific Time and 
Eastern Time, which refer to the time currently observed, whether it is 
standard time or daylight saving time.

Even Scharning
Time.is - exact time for any time zone

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