The Microsoft Outlook 2010, 2013, and 2016 are installed with the Calendar.
Open Microsoft Outlook.
Click the File menu and select Add Calendar.
In the Add Calendar dialog box, select the calendar you want to add.
If you want to add a new calendar, select New Calendar.
If you want to add an existing calendar, select the calendar you want to add.
Click OK.
You can add a calendar to Outlook by right clicking on the calendar icon and select Add Calendar.