Will the Chile DST change in 2019 affect CA UIM


Article ID: 130609


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DX Infrastructure Management NIMSOFT PROBES


Chile's Ministry of Energy has announced new dates for the start and end of Daylight Saving Time, starting in 2019.

From 2019, Chileans will turn the clocks back one hour at the end of Daylight Saving Time (DST) at midnight between the first Saturday night and Sunday morning of April every year. They will then turn clocks forward again to begin DST on the first Saturday/Sunday of September.

The first change following the new dates will be on the night between Saturday, April 6, 2019 and Sunday, April 7, 2019.

Chile Standard Time (CLT) is 4 hours behind Coordinated Universal Time (UTC). During Daylight Saving Time, clocks are set forward one hour to Chile Summer Time (CLST), at UTC-3.

What precautions should be taken to prevent any problem related to DST change in CA UIM?




All the items below must be validated:

A) Ensure the Operating System DST(Daylight Saving Time) end date is correct, on April 7, 2019 at 12:00 AM.

B) Ensure the JRE tzdata on the UIM machines have the update for DST change:

The change for the new DST for Chile was released in tzdata2018f.

Note: Up to tzdata2018e release, you could download from iana: java -jar tzupdater.jar -l https://data.iana.org/time-zones/releases/tzdata2018e.tar.gz
But since tzdata2018f release, the tzupdater is failing to parse the asia file

The workaround is in this URL: https://mm.icann.org/pipermail/tz-announce/2018-October/000052.html

The translator to rearguard format now rewrites the line "Rule Japan 1948 1951 - Sep Sat>=8 25:00 0 S" to "Rule Japan 1948 1951 - Sep Sun>=9  1:00 0 S".
This caters to zic before 2007 and to Oracle TZUpdater 2.2.0 and earlier. 


As announced in <https://mm.icann.org/pipermail/tz-announce/2018-October/000052.html> a rearguard-format tarball <https://web.cs.ucla.edu/~eggert/tz/release/2018g/tzdata2018g-rearguard.tar.gz> is intended to be usable by programs that don't yet support the timestamps in question. 

The other option is downloading the latest tzdata from the https://data.iana.org/time-zones/releases/ and manually edit the asia file. 

Release 2018f - 2018-10-18 00:14:18 -0700

  Most of Chile changes DST dates, effective 2019-04-06.

  Changes to future timestamps

  Most of Chile will end DST on the first Saturday in April at 24:00 mainland time, and resume DST on the first Saturday in September at 24:00 mainland time.  
  The changes are effective from 2019-04-06, and do not affect the Magallanes region modeled by America/Punta_Arenas. (Thanks to Juan Correa and Tim Parenti.)
  Adjust future predictions accordingly.

The JRE tzdata version should be tzdata2018f or above.

Here are the steps to check the version and update the tzdata:

1) Download the Java Time Zone Updater Tool

2) Extract the Time Zone Updater 2.2.0 (tzupdater-2.2.0.zip) file and save the tzupdater.jar file in the C:\Program Files (x86)\Nimsoft\jre\jre8u102\bin\ directory

3) In a DOS-Prompt window as Administrator, navigate to the C:\Program Files (x86)\Nimsoft\jre\jre8u102\bin\ directory and run the following syntax to check the version of tzupdater.jar file:
java -jar tzupdater.jar -V

In a DOS-Prompt window as Administrator, navigate to the C:\Program Files (x86)\Nimsoft\jre\jre8u102\bin\ directory and run the following syntax to manually patch the installation with the tzdata2018g (timezone data): 
java -jar tzupdater.jar -l https://web.cs.ucla.edu/~eggert/tz/release/2018g/tzdata2018g-rearguard.tar.gz

If the machine does not have access to download the tzdata file, download it manually and place in a temporary folder (C:\Temp), then run the following syntax to update the JRE:
java -jar tzupdater.jar -l file:///C:/Temp/tzdata2018g-rearguard.tar.gz