If an event from your family tree is not showing up in your calendar, please try the following:
On your family site move your mouse over the 'Home' tab and click on 'Family events'.
Check the event you are looking for in the list of events given on the Events page.
If you don't see the event here, make sure that the date is entered correctly in the tree. If you entered the date manually in past, try to re-enter it, choosing the date from the calendar date picker:
In addition, please update the calendar settings on your family site. To do so, go to the 'Family events' page as described above, and click on 'Calendar settings'.
Un-check the option to import events from the tree, and then save settings. Then re-check the option and save the settings again.
Note: If you are editing your tree in Family Tree Builder software, please make sure to edit the date you entered there and sync your tree.