April 2010 - tz - lists.iana.org

[somehow OT] "undoing" manual tzdata compilation on a Mac
by Mariano Absatz - El Baby April 3, 2010

April 3, 2010

Hi, I know Argentina has a long history of doing last minute changes about our timezones including inter-provincial anarchy. However, tzdata is easy enough to quickly adapt to this changes, and if you're somehow savvy, it is quite easy to fix things on your own. Last October, Argentina decided not to apply DST this (Southern) summer on the last minute and this was reflexed on tzdata2009p published on October 26th. Since Apple didn't immediately made this changes, knowing that OS X is actually running on top of some kind of BSD and actually finding zic and /usr/share/zoneinfo in it, I volunteered "fixing" a friend's macbook pro. I simply compiled the southamerica file from tzdata2009p and that was it... right? wrong! This actually made the mac go somehow crazy since it also uses some ICU files which I don't know how to handle. My friend ended up using Chile's time during the summer and Uruguay's time after Uruguay's DST period ended. Since a week ago the non-existent DST for Argentina would have ended, I told him to try again Argentina's time but it keeps being inconsistent. Another mac he has at home has now the correct time. Does anyone know how to restore the original OS X tzdata files without reinstalling the OS? I know nothing about its packaging system... Mac users seem to rely on "Apple update" service but I probably f##k'd it up when I overwrote some files under /usr/share/zoneinfo. Any help (or links to better places) will be greatly appreciated. -- Mariano Absatz - "El Baby" baby(a)baby.com.ar www.clueless.com.ar -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- I haven't lost my mind, I have it backed up on tape somewhere. -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- * TagZilla 0.066 * http://tagzilla.mozdev.org

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Asia/Taipei has DST in 1979 between July 1st and Sep.30
by smallufo April 2, 2010

April 2, 2010

According to Taiwan's CWB : http://www.cwb.gov.tw/V6/astronomy/cdata/summert.htm Taipei has DST in 1979 between July 1st and Sep.30 but Olson DB doesn't mention this.

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FW: Questions about tzdata implementations
by Olson, Arthur David (NIH/NCI) [E] April 1, 2010

April 1, 2010

I'm forwarding this message from Chad Eberle, who is not on the time zone mailing list. Those of you who are on the list, please direct replies appropriately. --ado -----Original Message----- From: Chad Eberle [mailto:ceberle@co.pierce.wa.us] Sent: Monday, March 29, 2010 1:15 To: tz(a)lecserver.nci.nih.gov Subject: Questions about tzdata implementations I apologize if this isn't the right place for this question, but would appreciate any help with tracking down the answer to these questions. Background: We have Java web services that send back date/time values with GMT offsets adjusted for DST following historical rules that match what I see in the northamerica file for America/Los_Angeles. Our client code is largely JavaScript, and depending on the operating system, will sometimes be incongruous about when DST starts or ends (dates before 2007 on Windows and before 1950. As one can imagine, this has caused a few problems. I can't seem to find any solution for the JavaScript end, so I was planning on writing one myself (if anyone knows of a solution, I'd appreciate any pointers). My questions: 1) Is there some reference implementation for the algorithm that selects the correct rule for a given date? 2) For the general US rules, there is a rule that says DST started in 1945 on Aug 14 at 23:00; however, my tests in Java indicate that DST was observed from Feb 9 1942 through Sep 30 1945, continuously. The latter matches the historical information I've found. Is this rule superfluous? Again, any tips would be appreciated. --Chad Eberle

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