I know is too probably too late already, but perhaps for future reference. For Drupal 7, this what you can do:
- setup calendar using views. if you do not know how to do it, refer to the module documentation.
- this calendar is for all users on the site to use
if you want certain individual user to have his own calendar with listed events that he adds himself, and only him can see, and it is listed in tab menu of his user menu, then you can do this:
- clone that calendar views and rename it to something
- on the advance setting, add 'relationships' of 'content:author'
- add 'contextual filter' of 'user:uid'
- change the order of contextual filter so user:uid is listed first
- add to the path: /user/%/calendar.........../month
- do the same thing to week, day and year if you want
- on the menu, choose 'menu tab' and 'user menu'
that will display additional tab on individual user menu.
Just another note on this,
If you are using the mini calendar block you will need to edit the contextual filter for User ID and select "Provide default value" and set it to "User ID from URL". Since blocks do not get URL's like pages do, it must be told where to grab the user id from.
Hope that helps someone!