It is often helpful to know what week, out of the possible 52 weeks in a calendar year, a particular week is. Here’s how to tell Apple’s.app Calendar to show week numbers.
- Open Calendar.app(or iCal on earlier versions of macOS) on your Mac.
- Choose Preferences from the Calendar menu.
- Click Advanced in the Toolbar.
- Click the box to the left of Show week numbers.
- Close the window.
Now look at your Calendar. You’ll see gray week numbers along the left margin of your Calendar.