Re: Time zone detection

[Maxim Solodovnik <so...@gmail.com>]

I have started a thread in Wicket-dev mailing list:
http://wicket.markmail.org/thread/n6wlcov3ff6eq5t5
Will track it and maybe will propose the patch


On 22 July 2014 20:19, Maxim Solodovnik <so...@gmail.com> wrote:

> I have sample code to determine which months/dates DST switch takes place
>
> https://svn.apache.org/viewvc/openmeetings/branches/3.0.x/src/main/webapp/js/openmeetings_functions.js?revision=1562780&view=markup
>
> line ~50
> The code might be enhanced to get actual hours DST switch taking place
>
>
> On 22 July 2014 20:15, Robert EL <ro...@gmail.com> wrote:
>
>> Thanks you, Maxim.
>>
>> I will create the quickstart, because the 6.16.0 version doesn't
>> resolve the problem (it has the same code in the getTimeZone method).
>>
>> However, I think this problem is not easy to resolve, because this
>> method return the best guess that wicket can do using the GMT and DST
>> offset provided by the browser.
>>
>> Think in this case:
>>
>> 1. User is in the GMT-0 time zone.
>> 2. Wicket list all the available time zone ID with the same GMT and
>> DST offset. This is the list for GMT-0:
>>
>> Africa/Casablanca
>> Africa/El_Aaiun
>> Atlantic/Canary
>> Atlantic/Faeroe
>> Atlantic/Faroe
>> Atlantic/Madeira
>> Eire
>> Europe/Belfast
>> Europe/Dublin
>> Europe/Guernsey
>> Europe/Isle_of_Man
>> Europe/Jersey
>> Europe/Lisbon
>> Europe/London
>> GB
>> GB-Eire
>> Portugal
>> WET
>>
>> 3. Wicket has to decide which is the correct time zone without other
>> information.
>>
>> If you read the code of getTimeZone method you will see this comment:
>>
>> // this is a best guess... still the start and end of the DST should
>> // be needed to know to be completely correct, or better yet
>> // not just the GMT offset but the TimeZone ID should be transfered
>> // from the browser.
>>
>> One solution could be identify the country of the user using his IP
>> address. But databases are never perfect or user well could be a
>> remote client of some provider from absolutely different time zone.
>>
>> Regards.
>>
>> 2014-07-22 12:46 GMT+01:00 Maxim Solodovnik <so...@gmail.com>:
>> > I believe we should
>> > 1) update to the latest 6.16.0 release
>> > 2) In case still an issue file JIRA issue against WICKET:
>> > https://issues.apache.org/jira/browse/WICKET
>> >
>> > Here is the small how-to
>> https://wicket.apache.org/start/quickstart.html
>> > create quick start
>> > I believe this issue can be fixed in a day or so
>> >
>> > Could you create such quickstart?
>> >
>> >
>> > On 22 July 2014 18:27, Robert EL <ro...@gmail.com> wrote:
>> >>
>> >> Hi all,
>> >>
>> >>
>> >> I'm using OM 3.0.3 and I've a problem when I create an event in the
>> >> Scheduled Meeting. OM returns the fields StartDay and EndDay with one
>> >> day less than the day selected (month view).
>> >>
>> >>
>> >> I've had tracing the bug and I've found the problem in the method of
>> >> detecting the time zone of the client. The method getTimeZone() of
>> >> class ClientProperties (wicket-core-6.14.0.jar) always return the
>> >> first time zone ID that match with the GMT and DST offset of the
>> >> user's browser.
>> >>
>> >>
>> >> In my case, it's returning “Africa/Casablanca” instead of
>> >> “Atlantic/Canary”. “Africa/Casablanca” is the time zone of Morocco and
>> >> it has a different daylight saving behavior from Jun 29 to July 28
>> >> (month of ramadan:
>> >>
>> >>
>> http://www.oracle.com/technetwork/java/javase/tzdata-versions-138805.html
>> ).
>> >>
>> >>
>> >> So, OM set StartDay and EndDay with one hour less when it applies this
>> >> time zone to the day selected (these variables are initialized to
>> >> 00:00:00 before apply the current time).
>> >>
>> >>
>> >> Have you thought about adding a complementary method for guessing the
>> >> TimeZone of the client? IP-based Geolocation, for instance?. Will OM
>> >> continue using this method in future releases?.
>> >>
>> >>
>> >> Regards.
>> >
>> >
>> >
>> >
>> > --
>> > WBR
>> > Maxim aka solomax
>>
>
>
>
> --
> WBR
> Maxim aka solomax
>



-- 
WBR
Maxim aka solomax