
If you don’t receive calendar alerts on Mac
If you set an alert to occur before a calendar event but aren’t receiving the alert in Notification Centre, there are several possible solutions.
- Make sure alerts aren’t turned off in Calendar settings. In the Calendar app  on your Mac, choose Calendar > Settings, click Alerts, then select “Show shared calendar messages in Notification Centre” and “Show invitation messages in Notification Centre”. on your Mac, choose Calendar > Settings, click Alerts, then select “Show shared calendar messages in Notification Centre” and “Show invitation messages in Notification Centre”.
- Make sure alerts aren’t turned off in Notifications settings. Choose Apple menu  
- Make sure a Focus isn’t active when you want to receive alerts. See Turn a Focus on or off. 
- Make sure event alert times are set correctly. Choose Calendar > Settings, click Alerts, then choose an alert time other than None for Events, All Day Events or Birthdays. 
- Make sure you set up the alert properly. See Set alerts for an event. 
- If the alert is set to send an email, make sure your email address is correct in your card in Contacts. See Edit contact info.