Tuesday, February 27, 2007

Need to upgrade Java for U.S. Daylight Saving Time Changes


On the Sun Java website (link) is the following posting:

Daylight Saving Time (DST) is a system of handling the changing amounts of daylight throughout the year. The goal of DST is to maximize the daylight hours available during typical waking hours. By adjusting clocks ahead a standard amount, usually an hour, people can have more daylight available during their typical work day. For example, suppose you wake daily at 7:00 AM. In the spring, the sun rises earlier each day. Instead of waking up at 6:00 AM to take advantage of the daylight, DST observers move their clocks ahead an hour. The effect is that they can continue to wake at 7:00 AM according to the clock and enjoy more daylight. In the fall, people set their clocks back an hour as sunrise happens later each day.

The United States has planned a change to its DST observance beginning in 2007. The Energy Policy Act of 2005 mandates that DST will start on the second Sunday in March and end on the first Sunday in November. In 2007, the start and stop dates will be March 11 and November 4, respectively. These dates are different from previous DST start and stop dates. In 2006, the dates were the first Sunday in April (April 2, 2006) and the last Sunday in October (October 29, 2006).

The Java Runtime Environment (JRE) stores rules about DST observance all around the globe. Older JREs will have outdated rules that will be superseded by the Energy Policy Act of 2005. As a result, applications running on an older JRE may report incorrect time from March 11, 2007 through April 2, 2007 and from October 29, 2007 through November 4, 2007.

If you are concerned about application failures that may result from these DST changes, you should update your Java Runtime Environment. If you have 1.4.2_05 or 1.4.2_06, which many of you with Discoverer will have, then you should upgrade your clients to 1.4.2_13 by downloading it from the Sun website. If you are unable to download the update, Sun has provided a utility that will upgrade the timezone elements of your current install.

Note: The latest information I have is that there is no need to upgrade the Java on the server.

Download and install 1.4.2_13
To remove the Sun JRE 1.4.2_xx and re-install the correct version, use this workflow:

  1. Download the Sun JRE 1.4.2_13 from the Sun website. It can be found here:http://java.sun.com/j2se/1.4.2/download.html
  2. On this page, look for and click on the Download J2SE JRE link.
  3. On the next page, you are required to read and accept the license agreement.
  4. After checking the box labeled "Accept License Agreement", download the software labeled "Windows Offline Installation, Multi-Language". This file is about 15Mb in size *.
  5. Either you or one of your IT staff should now connect to your machine as a local administrator and install the software. Just follow the onscreen prompts.
  6. When done, you will need to restart the computer. When the system reboots, you will need to disable the automatic upgrade mechanism ** by following the remainder of these steps.
  7. From the Windows Start menu, select Settings > Control Panel.
  8. Double-click the icon for the Java ™ Control Page. It is usually named either Java or Java Plug-in.
  9. When the Java Control Panel opens, click the Update tab.
  10. Uncheck the box labeled "Check for updates automatically".
  11. Click the OK button to save and exit.

* The file that is downloaded is an executable called: jr2e-1_4_2_13-windows-i586-p.exe.
** Even though you may have already told the previous version not to automatically upgrade, when you install 1.4.2_13 this will have been reset.

Download and run the updater script
There is a tool on the Sun Java website (link) that you can download to upgrade the time zone data for your Java. To get this tool you will need to be registered for support with Sun. This is a very easy process. If you have not registered for support with Sun you will find a link called Register Now on the page (link).

To download and run the updater script, use this workflow:

  1. On the Sun Java(TM) 2 SDK, Standard Edition - US DST Timezone Tool 1.0.1 page, click the link for the download and save the file (tzupdater-1.0_1.zip) in a safe place on your system.
  2. Unzip the file. It will create a folder called tzupdater2007a
  3. Launch a Windows command prompt session
  4. Navigate to the folder called tzupdater2007a
  5. Execute this command: java -tar tzupdater.jar -t

Some Daylight Saving Time Links:

About Daylight Saving Time

When does Daylight Saving Time begin and end

Tuesday, February 13, 2007

What would you like to see?

Hi everyone
Is there anything about Discoverer that has been bugging you, something where a posting might help? Perhaps you have a desire to know how to do something, or perhaps you would like to see a visual aid for working through a workflow?

Drop me a line to michael@learndiscoverer.com and I will see what I can do.