1. Display the 'Developer' tab in Excel, if it is not already displayed. Click the 'Microsoft Office Button' and then click 'Excel Options.' In the category labeled 'Popular,' under 'Top options for working with Excel,' check the box labeled 'Show Developer Tab in the Ribbon' and click 'OK.'
2. Click 'Insert' in the 'Controls' group on the 'Developer' tab. Under 'ActiveX Controls' click the 'More Controls' button. This button will look like a hammer and a wrench. The 'More Controls' dialog box will appear.
3. Select 'Calendar Control 12.0' and click 'OK'. Right-click the area into which you wish to insert the calendar. The calendar will then be displayed on your workbook. The current month will be displayed.
4. Edit the calendar by right-clicking on it and selecting 'Calendar Object' and then 'Properties.' This will allow you to change the dates in the calendar. If you wish to edit the font, color or any other properties of the calendar, right-click the calendar and choose 'Properties.'