Sometimes, you don't want to continue watching a show or you don't want it to show up on your calendar. To hide it: 

From the Up Next to Watch Section on the Dashboard:

Underneath the poster is the ø symbol.  Click ø and then choose, Yes, Hide It!  This will hide this show from your progress and the Up next to watch on the dashboard.

From your Progress:

The ø will hide your watched progress from the progress page as well as the Up next to watch area of the dashboard.

From the Calendar:

Clicking on the ø on the calendar will hide the show from all calendar views.

On the iOS app: 

Long pressing on the listing from the calendar or progress will display a menu with hiding options.

To restore your hidden shows:

Go to the Hidden Items section of your settings.  Any show that you click on will be restored.  The top section is the shows you've hidden from your calendar.  Once you've scrolled through the hidden calendar items, the hidden shows from your progress are visible.  To restore a show to both calendar and progress, click on the show poster in both sections.