TimeZone Updater Tool/Project, where would we put it?

Alan Bateman Alan.Bateman at oracle.com
Mon Dec 2 09:23:51 UTC 2019

On 29/11/2019 15:08, Andrew Leonard wrote:
> The .zip contains the tzupdater "program" along with the latest tzdb.dat.
> The user then unzips this and runs the "program" in the desired "mode".
> Currently, it distinguishes jdk8 from jdk11+ only, and the only 
> version update is that contained within the new tzdb.dat eg."2019c". 
> So you can run the tool in "discovery" mode which will simply print 
> out what tzdb version each JDK is at...
> The basis of updating any jdk8,11,13,.. with the tzdb.dat is based 
> upon the fact that it's currently producing a "rearguard" tzdb.dat 
> which is compatible with all these versions... This would need 
> changing going forward when vanguard is used, and perhaps with that in 
> sight it maybe best to update the tool to only patch the same versions 
> from which the updater was built from...
> I can thus see several improvements being discussed here:
> - Better JDK version detection
> - Possibly provide release/version file update somewhere to identify 
> the update other than just in the tzdb.dat
> - Make the tool "version" specific,ie. a jdk13 "updater.zip" will only 
> patch a jdk13 JDK.
I assume "program" means something platform specific or maybe you mean a 

You haven't mentioned it yet but I assume it needs to update more than 
just tzdb. For JDK 9+ at least, it will need to update the TZ data in 
the packaged module (java.base.jmod) so that any replication with jlink 
will use the new TZ data too.

There are lots of other questions but it might be better if you started 
a document to capture the needs, issues, and the possible technical 
approaches. That should help the discussion and help to see whether it 
make sense or not for something like this to be part of the JDK build or 
a separate patching tool.


More information about the jdk-dev mailing list