JIRA is a critical part of the software development life cycle and is used to store many kind of issues. Users rely on JIRA to check whether their daily tasks and managers use JIRA to keep track of their projects. JIRA administrators sometimes need to perform maintenance activities that require downtime for users. As a good practice, all the users, or at least the stakeholders, should be notified, but to avoid any surprises for the user, it's a good idea to give them an indication of any planned downtime.
JIRA has an option to add an announcement banner, which is visible all across the JIRA instance just after the main navigation. Perform these steps to add the announcement banner:
Navigate to Administration | System | Announcement Banner (under USER INTERFACE).
In the Announcement text area, enter your message and click on the Set Banner button. You can also include HTML tags. Select Visibility Level as Public - Show to anyone to show this announcement to users...