Sometimes you may need to mark a visit as "Not Serviced" due to weather, the customer saying it didn't need servicing this time, etc, etc.
To do that, when you are on the schedule screen, click the visit you want to mark as "Not Serviced". This will bring up the edit / close visit popup.
At the bottom of this popup is a red "Not Serviced" button.
Once you click it, you will see a popup asking for a reason.
Enter the reason, then click the blue "Not Serviced" button and it will be saved.
It will also be marked in red on your schedule so you can easily see visits marked as "Not Serviced".