Pacific tz has wrong start/stop dates for DST

[David M. Karr]

Here in Seattle, on April 13, we're in daylight savings time. I've noticed since DST started that log files created by Java applications are an hour behind. I figured it had something to do with daylight savings time. Non-Java applications do not display this symptom.

If it matters, here's the output of "java -version":

java version "1.6.0_10"
Java(TM) SE Runtime Environment (build 1.6.0_10-b33)
Java HotSpot(TM) Client VM (build 11.0-b15, mixed mode, sharing)

I wrote a small test application that prints out relevant information about daylight savings time. I'll attach the test code, but the output it produces follows this. You'll see that as of today, it thinks DST is not in effect. It also shows that it thinks DST starts on April 26, and ends on October 25, which is not correct.

date[Mon Apr 13 13:04:01 PST 2009] zonename[Pacific Standard Time] dstSavings[3600000] usesDST[true] inDST[false] rawOffset[-28800000] offset[-28800000]
date[Mon Apr 13 13:04:01 PST 2009] inDST[false]
date[Wed May 13 13:04:01 PDT 2009] inDST[true]
date[Sat Jun 13 13:04:01 PDT 2009] inDST[true]
date[Mon Jul 13 13:04:01 PDT 2009] inDST[true]
date[Thu Aug 13 13:04:01 PDT 2009] inDST[true]
date[Sun Sep 13 13:04:01 PDT 2009] inDST[true]
date[Tue Oct 13 13:04:01 PDT 2009] inDST[true]
date[Fri Nov 13 13:04:01 PST 2009] inDST[false]
date[Sun Dec 13 13:04:01 PST 2009] inDST[false]
date[Wed Jan 13 13:04:01 PST 2010] inDST[false]
date[Sat Feb 13 13:04:01 PST 2010] inDST[false]
date[Sat Mar 13 13:04:01 PST 2010] inDST[false]
date[Sun Apr 26 00:00:00 PST 2009] inDST[false]
date[Mon Apr 27 00:00:00 PDT 2009] inDST[true]
date[Sun Oct 25 00:00:00 PDT 2009] inDST[true]
date[Mon Oct 26 00:00:00 PST 2009] inDST[false]

[David M. Karr (davidmichaelkarr)]

The thread I started on c.l.j.p might have some relevant information: <http://groups.google.com/group/comp.lang.java.programmer/browse_thread/thread/dfa4f1e81bf06bc0#>.

As a result of this discussion, I replaced the hard file "/etc/localtime" with a symlink to "/usr/share/zoneinfo/US/Pacific". This appears to "fix" the problem, but I have no idea why (I'm waiting for a response to that question). This is even more intriguing, as before I replaced the hard file with a symlink, I did a "cmp" on the two files, which showed they were identical.

Before I did the replacement, an "ls -l" on these files showed the following:

davidkarr@davidkarr-desktop$ ls -lt /usr/share/zoneinfo/US/Pacific /etc/localtime
-rw-r--r-- 1 root root 2819 2009-04-06 08:30 /etc/localtime
-rw-r--r-- 1 root root 2819 2009-03-30 07:56 /usr/share/zoneinfo/US/Pacific

Also as a result of this discussion, I downloaded and ran the "tzupdater" tool, but this had no effect on the symptom.