Set event alerts and receive notifications in Calendar on Mac
Be notified of an upcoming Calendar event by setting one or more alerts. An alert can place a notification on your screen, send an email or open a file.
When an event notification appears, you can close it or temporarily dismiss it. If the event has a location specified, you can also get directions.
Set an alert for an event
In the Calendar app
on your Mac, double-click or force click an event to view event details, then click the event’s time.Click the Alert pop-up menu, then do one of the following:
Choose a time or day.
Choose Time to Leave. This option only applies if you added a location. For information about how time to leave is calculated, see Add a location.
Choose Custom, then choose an option:
Message with sound: Displays a notification on the screen and makes a sound.
Email: Sends you an email.
Open file: Opens the file you choose.
To add another alert, place the pointer over the Alert pop-up menu, then click the Add button
.You can set only one alert for Exchange events.
To remove an alert, click the Alert menu, then choose None.
Turn off alerts for a calendar
In the Calendar app
on your Mac, Control-click the name of the calendar in the calendar list, then choose Get Info.If you don’t see the calendar list on the left, choose View > Show Calendar List.
Select “Ignore alerts”, then click OK.
Show or hide all Calendar alerts
On your Mac, choose Apple menu
Click Calendar on the left, then select whether you want invitation notices and event alerts to appear as banners or alerts, or not to appear.
Respond to event notifications
On your Mac, move the pointer over the event notification, then do any of the following:
Dismiss the notification: Click the Close button
.Temporarily dismiss the notification: Click Options, then click Snooze (Automatic) or choose a snooze duration.
Get directions to the event location: Click Options, then click Directions.
See more details: Click the notification to open the event in Calendar, or click the arrow
to see details in the notification.Change Calendar notification settings: Click the arrow
, click the More button 
, then click an option. The Notification Preferences option opens the Calendar notification pane in System Preferences.
If you choose Snooze (Automatic), the notification reappears in 9 minutes or at the start of the event, whichever is sooner. If you choose Snooze (Automatic) after the start time, it reappears in 9 minutes.