Problem

1. Custom fields are displayed in the wrong date locale. Example (Polish locale. Compare that to the Created, Updated and Due date fields):
   
2. The System Date and System Installation Date fields in Confluence Admin >> System Information are shown in the wrong date locale as well:
   
   
   

The following appears in the application.xml (in the Confluence Support Zip):

<user.language.format>pl</user.language.format>
<user.country.format>PL</user.country.format>

The Polish locale here is shown as an example

Cause

1. A recent change in JDK 7: http://blog.ej-technologies.com/2011/12/default-locale-changes-in-java-7.html

2. The Global Environment variable is overriding the user.language.format and user.country.format system properties, such that the JAVA_OPTS contains this:

   -Duser.language.format=pl -Duser.country.format=PL

Resolution

• Override the JVM defaults by adding the following to your System Properties (set the locale according to the locale of your choice):

  -Duser.language.format=en -Duser.country.format=US

  See Configuring System Properties for more details on how to do this

• Restart Confluence