[tz] More on EU/UK/Brexit clock changes

Michael H Deckers michael.h.deckers at googlemail.com
Fri Feb 14 23:01:14 UTC 2020


    On 2020-02-12 01:57, Paul Eggert wrote about the
    study from the House of (Time) Lords:

> On 2/11/20 5:36 PM, Chris Woodbury wrote:
>> The "Time Lords" subcommittee has released yet another study.  Find 
>> it at:
>>
>> https://publications.parliament.uk/pa/ld5801/ldselect/ldeucom/15/15.pdf
    ...
> They also mentioned us at some length on page 25 about how to best 
> implement UTC+1 year-round in the UK.


    In the IANA statement SCT0004 referenced on page 22,
    I read:

      >>  The notion of permanent summertime is not supported by the 
POSIX.1-2017
      >>  standard[4], which covers most of the computer servers in the UK.

    This is correct in the sense that POSIX does not mention
    summer time -- but POSIX mentions
      "alternative (dst - such as Daylight Savings Time) timezone"
    in addition to standard time.

    And a TZ string may well specify that the "alternative" time
    is "permanent" (in the sense of being in force throughout the
    year), for instance with:
                        EET-2/BST-1,J1/01:00,J365/24:00
    so that POSIX does support permanent "alternative time zones".

    Hence it is not clear to me exactly which unsupported feature
    of POSIX is meant in the quote above.

    Michael Deckers.



More information about the tz mailing list