To change the 'remember me' cookie duration, perform the following steps:

1. Open the seraph-config.xml file from the JIRA_INSTALL/atlassian-jira/WEB-INF/classes directory in a text editor.

2. Locate the autologin.cookie.age line, and change the value of param-value to the desired number in seconds:

<init-param>
    <param-name>autologin.cookie.age</param-name>
    <param-value>1209600</param-value>
</init-param>

3. Restart Jira for the changes to apply.