IBM Time Zone Update Utility for Java - Version 1.7.16j

The IBM Time Zone Update Utility for Java (JTZU) applies Daylight Saving Time (DST) changes directly to your Java SDKs and JREs.


JTZU updates the time zone information in IBM-supplied releases and service refreshes of the Java™ SDK and JRE. With this tool, you can adopt changes to DST when you are unable to apply a service refresh, or when a service refresh is not yet available that incorporates the time zone changes you need.

JTZU searches your system for IBM SDKs and JREs and updates each one found. The tool works in two modes:

You can use JTZU to update individual Java instances or multiple instances on local or network drives. The update process can be run automatically without user intervention, or you can control which JREs and SDKs are updated. The flexibility built in to the tool means that you can adapt the way it runs to suit your needs. For further information about downloading, installing, and using JTZU, see the Readme file.

JTZU 1.7.16j delivers time zone changes for:

JTZU is supported on AIX, Solaris, HP-UX, Linux, Windows, and z/OS. For more detailed information about the platforms supported and the SDKs and JREs discovered and updated by JTZU, see the Readme file.

DST changes can be applied to Java on IBM i systems using the TZUPATCH tool, which is included in the non-z/OS JTZU download package.

JTZU downloads

Before you download the code, read the license.

Platform JTZU download
AIX, Solaris, HP-UX, Linux, Windows and IBM i

To see which time zone updates are included for different versions of JTZU, see Olson time zone updates for Java JRE and SDK service refreshes for IBM products

Applying IBM product maintenance that contains earlier time zone data will remove the updates applied by this tool. You must rerun this tool to restore the time zone data to the latest level.

Updates made to Java time zone data by JTZU are not managed by any of the formal change control mechanisms for servicing IBM software products.

Technical support

If you experience a problem using JTZU, check IBM Time Zone Update Utility (JTZU) known problems and diagnostic information. This document describes how to diagnose problems with JTZU and details the information that will be needed by the JTZU support team to help you.

For technical support on JTZU, including questions or feedback, send an e-mail to This address is monitored on weekdays during normal working hours. We aim to reply within two working days.

If you have a licence that includes product support, you can also report problems using the standard IBM product support process. You must identify the IBM product being updated when the problem occurs.

Leap seconds

In coordinated universal time (UTC) a day normally consists of 86400 seconds. However, every few years there is an extra second called a "leap second". The leap second is always added as the last second of the day, and always on December 31 or June 30. For example a leap second will be inserted at the end of June 30 2015.

The JVMs from IBM tolerate but do not utilize leap seconds, so they do not need updating with timezone data which has leap second information to work correctly. No action is required by customers to cope with the leap seconds.

Change history

30 Nov 2016 Updated to 1.7.16j
07 Nov 2016 Updated to 1.7.16i
24 Oct 2016 Updated to 1.7.16h
05 Oct 2016 Updated to 1.7.16g
06 Jul 2016 Updated to 1.7.16f
24 Jun 2016 Updated to 1.7.16e
25 Apr 2016 Updated to 1.7.16d
24 Mar 2016 Updated to 1.7.16c
16 Mar 2016 Updated to 1.7.16b
19 Feb 2016 Updated to 1.7.16a
12 Oct 2015 Updated to 1.7.15g
17 Aug 2015 Updated to 1.7.15f
17 Jun 2015 Updated to 1.6.15e
28 Apr 2015 Updated to 1.6.15d
22 Apr 2015 Updated to 1.6.15c
30 Mar 2015 Updated to 1.6.15b
03 Feb 2015 Updated to 1.6.15a
25 Nov 2014 Updated to 1.6.14j
04 Nov 2014 Updated to 1.6.14i
17 Sep 2014 Updated to 1.6.14g
12 Aug 2014 Updated to 1.6.14f
19 Jun 2014 Updated to 1.6.14e
14 May 2014 Updated to 1.6.14c.
31 Mar 2014 Updated to 1.6.14b.
12 Mar 2014 Updated to 1.6.14a.
20 Dec 2013 Updated to 1.6.13i.
05 Nov 2013 Updated to 1.6.13h.
27 Sep 2013 Updated to 1.6.13f.
11 Jul 2013 Updated to 1.6.13d.
14 Mar 2013 Updated to 1.6.13b.
05 Nov 2012 Updated to 1.6.12i.
09 Oct 2012 Updated to 1.6.12f.
24 Jul 2012 Updated to 1.6.12d.
13 Apr 2012 Updated to 1.6.12c.
09 Mar 2012 Updated to 1.6.12b.
16 Dec 2011 Updated 1.6.11n to fix a bug where the tool does not detect Java 6 SR10.
28 Nov 2011 Updated to 1.6.11n.
27 Oct 2011 Updated to 1.6.11m.
21 Oct 2011 Updated to 1.6.11l.
26 Sep 2011 Updated to 1.6.11j.
8 Jul 2011 Updated to 1.6.11h.
6 May 2011 Updated to 1.6.11g.
13 Apr 2011 Updated to 1.6.11f.
22 Mar 2011 Updated to 1.6.11d.
11 Mar 2011 Updated to 1.6.11c.
7 Feb 2011 Updated to 1.6.11b.
3 Dec 2010 Updated to 1.6.10o.
10 Nov 2010 Updated to 1.6.10n.
02 Sep 2010 Updated to 1.6.10l.
10 Aug 2010 Updated to 1.6.10k.
02 Jun 2010 Updated to 1.6.10j.
26 Mar 2010 Updated to 1.6.10f.
26 Feb 2010 Updated to 1.6.10b.
25 Nov 2009 Updated to 1.6.9s.
10 Nov 2009 Updated to 1.6.9p, added support for IBM i.
22 Jun 2009 New download page created, old page archived.

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