[tz] Spain may change time

[Michael Deckers]

   On 2016-12-13 22:10, Paul Eggert wrote about Planesas' paper:


> That paper is quite helpful. Attached is a proposed patch to fix the tz entries
> to agree with the paper's for Europe/Madrid. There are still several gaps
> outside Madrid (and even in Madrid during the chaos of its fall in 1939).

   Perhaps the instant of the switch to time zone
   time for Europe/Madrid could also be corrected.

   The Royal Decree of 1900-06-26 quoted by Planesas, online at
       [https://www.boe.es/datos/pdfs/BOE//1900/209/A00383-00384.pdf]
   says in its article 5 (my translation):
       These dispositions will enter into force beginning with the
       instant at which, according to the time indicated in article 1,
       the 1st day of January of 1901 will begin.
   The time in article 1 is GMT = WET. Thus:

     - Zone   Europe/Madrid   -0:14:44  -  LMT  1901 Jan  1  0:00s
     + Zone   Europe/Madrid   -0:14:44  -  LMT  1900 Dec 31 23:45:16

   Michael Deckers.