Notifications will, if activated, always be displayed for all users at the top of the SAP Process Mining by Celonis 4.2 window.
This is a great tool to publish announcements!
Every user can however remove the notification with the small 
in the uper right corner.
To add a new notification, click on 
.
Enter a title and a notification message.
Don't forget to activate your notification with the checkbox:
To schedule the notification, you are asked to provide a starting and an ending timestamp:
Save your settings with 
.