ICU and "Sources for Time Zone and Daylight Saving Time Data"

Paul Eggert eggert at
Tue Apr 13 06:24:28 UTC 2004

"Steven R. Loomis" <srl at> writes:

> Java 1.4 has historical time zones (I believe also from the tz
> data?)

Thanks for letting me know about this.  I looked through the source
code (in J2SE-1.4.2/java/ for this.  As far as I can tell, the
historical time zone data is in J2SE-1.4.2/j2se/jre/lib/zi, in a
format that differs somewhat from the standard Olson format.  Also,
this information is not in every Java 1.4 implementation, though it is
in Sun's.  I can't find any supported way to convert from tz format to
Java format, so if the Java data are wrong there doesn't seem to be
any way to update them from the tz master.

Does the following snippet summarize this information correctly?

<li><a href="">Sun Java</a> releases since 1.4
contain a copy of a recent <samp>tz</samp> database in a Java-specific

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