If you create a meeting without the Calendar tool on the site, but add the Calendar tool later, you can add each meeting individually to the Calendar.
Go to Sign-up.
Select Sign-up from the site Tool Menu.
Select Modify.
To change any of the initial settings of the meeting, use the Modify option shown at the top of Meeting Details.
Select Show the other default settings.
The information described in How do I create a meetings? will be shown for editing the settings of your choice.
Check Publish to Calendar.
Select the checkbox next to Yes, publish the meeting to the Calendar tool.