When you get an email about an event like a flight, concert, or restaurant reservation, it's added to your calendar automatically – no need to copy over the details to your calendar.
These automatically added events are only visible to calendar owners. Sharing settings can be changed in Google Calendar settings or in individual events.
This new feature can be turned off!
If you don't want events from Gmail on your calendar, you can delete a single event from your calendar or change your settings so that events aren't added automatically. Here's how to turn off this feature:
Article posted by Lisa Bono