[tz] Europe/Dublin daylight saving time format confusion

[Sanjeev Gupta]

Hi,

Unlike other countries, Ireland sets it is "Summer Time" as "Ireland
Standard Time", and drops an hour in Winter (to GMT).

This has been discussed on the mailing list at length.  If your parser
cannot handle the negative DST, there is a "rearguard" collection of zone
files that provides compatibility, for now.

-- 
Sanjeev Gupta
+65 98551208     http://www.linkedin.com/in/ghane


On Thu, Mar 28, 2019 at 1:48 AM Guruswamy Basavaiah <guru2018 at gmail.com>
wrote:

> Hello,
>   Generated timezone files using the below command on release 2018e.
>    zic -L /dev/null -d output_dir  -y "sh yearistype.sh" europe
>
> zdump show daylight saving flag (isdst=1) is wrongly set for
> Europe/Dublin. Daylight saving time should start from March 31 and end
> on October 27.
> But here it shows reverse.
> zdump -v /home/basavaia/output_dir/Europe/Dublin | grep 2019
> /home/basavaia/output_dir/Europe/Dublin  Sun Mar 31 00:59:59 2019 UT =
> Sun Mar 31 00:59:59 2019 GMT isdst=1 gmtoff=0
> /home/basavaia/output_dir/Europe/Dublin  Sun Mar 31 01:00:00 2019 UT =
> Sun Mar 31 02:00:00 2019 IST isdst=0 gmtoff=3600
> /home/basavaia/output_dir/Europe/Dublin  Sun Oct 27 00:59:59 2019 UT =
> Sun Oct 27 01:59:59 2019 IST isdst=0 gmtoff=3600
> /home/basavaia/output_dir/Europe/Dublin  Sun Oct 27 01:00:00 2019 UT =
> Sun Oct 27 01:00:00 2019 GMT isdst=1 gmtoff=0
> Above Behavior is same in 2019a also.
>
> If I check the same on 2018a, it gives proper output.
> zdump -v /home/basavaia/2018a/Europe/Dublin | grep 2019
> /home/basavaia/2018a/Europe/Dublin  Sun Mar 31 00:59:59 2019 UT = Sun
> Mar 31 00:59:59 2019 GMT isdst=0 gmtoff=0
> /home/basavaia/2018a/Europe/Dublin  Sun Mar 31 01:00:00 2019 UT = Sun
> Mar 31 02:00:00 2019 IST isdst=1 gmtoff=3600
> /home/basavaia/2018a/Europe/Dublin  Sun Oct 27 00:59:59 2019 UT = Sun
> Oct 27 01:59:59 2019 IST isdst=1 gmtoff=3600
> /home/basavaia/2018a/Europe/Dublin  Sun Oct 27 01:00:00 2019 UT = Sun
> Oct 27 01:00:00 2019 GMT isdst=0 gmtoff=0
>
> Is my understanding correct?
> And this behavior is introduced in commit
> 127b4af7219e6df9253b34e390797c5527b8cc66
>
> I am not in this mailing list, please include my email id while responding.
> --
> Guruswamy Basavaiah
>
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