You have set the option "Send with iCalendar Event" in Onboarding notifications and your notification is sending an "all day event" invitation.
SAP Successfactors Onboarding 1.0
At present, we don't have an option to adjust the event duration. By default the invitation will be an all day event.
i-calendar, email, notification, onboarding, 1.0 , KBA , LOD-SF-OBD , Onboarding , How To