Use Notification Center on Mac
In Notification Center on your Mac, Today view shows details about your day—appointments, weather, birthdays, even a summary of what you have planned for tomorrow—and Notifications view shows notifications you missed.
Tip: To customize or stop notifications, click the Notifications preferences icon 
in the bottom-right corner of Notification Center.
Use Today view in Notification Center
On your Mac, click the Notification Center icon
in the menu bar, or swipe left with two fingers from the right edge of the trackpad.In Notification Center, click Today.
Click an item in a widget to see its details or take an action.
For example, click an item in the Weather widget to show the hourly and five-day forecasts. Or click a reminder’s checkbox to complete it.
Customize Today view Notification Center
On your Mac, click the Notification Center icon
in the menu bar, or swipe left with two fingers from the right edge of the trackpad.In Notification Center, click Today.
Do any of the following:
Customize a widget: Move the pointer over the widget, then click the Info button
that appears.Reorder widgets: Click Edit at the bottom of Today view, then drag a widget up or down.
Add or remove widgets: Click Edit (or the new widget count, if shown) at the bottom of Today view. To add an available widget, click its Add button
. To remove a widget, click its Remove button 
; the widget is moved to the list of available widgets. Get more widgets: Click Edit at the bottom of Today view, click App Store, then buy or download widgets. For more information about buying and downloading items, see Find, buy, and download apps.
Use Notifications view in Notification Center
On your Mac, click the Notification Center icon
in the menu bar, or swipe left with two fingers from the right edge of the trackpad.In Notification Center, click Notifications.
Click a notification to open the item in the associated app. For example, click a Mail notification to open the email in Mail.
When you open an item, it’s removed from Notifications view. To remove an item without opening it, move the pointer over it, then click the Clear button 
. Or click the button for a day to remove all of the day’s notifications.
You can turn Night Shift and Do Not Disturb on or off in Notification Center—just swipe down, then click the button.
When you turn on Night Shift, it stays on until midnight, sunrise, the next scheduled time to turn off (based on settings in Night Shift preferences), or you turn it off.
When you turn on Do Not Disturb, it stays on until midnight, the next scheduled time to turn off (based on settings in Notifications preferences), or you turn it off.
When Do Not Disturb is on, the Notification Center icon in the menu bar is dimmed. You don’t see or hear notifications arrive; they are collected in Notification Center where you can view them later.