From time to time it can happen, that you want to edit an existing time tracking type. For that you have to go to menu / settings / Time Tracking.
Now you can see all your existing time tracking types. When you want to edit one, you have to click on the three little dots in the right corner of the type. Then you have the choice between deleting and editing it. When you click on edit it will open a pop-up window, where you can edit all your time tracking type information (Name, Description and Icon).
The change in a time tracking type changes the existing time tracking entries with this type.