You do not get notifications for Activities such as Phone Calls, Appointments,etc before start time of the Activity.
SAP Cloud For Customer
Reproducing the Issue
Go to the Activities work center.
Go to the Appointments view.
Enter all mandatory fields and click Save.
You expect a notification to be sent to Organizer and Attendees before the start time of Appointment but no notification is received by them.
As per the standard functionality notifications will not be sent for Activities such as Phone Calls, Appointments,etc before start time of the Activity.
You can use workflow rules as per your use case to achieve this.
SAP Help Portal: Create a Workflow Rule
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