1. Load the Diary Screen on the day/week you wish to apply the Trip Zone and bring up the My Trip Zones popup.

  2. Tap on the Trip Zones you wish to enable then tap Apply.

  3. The selected Trip Zones will now be applied to the day you are on and indicate which accounts are in the zone by colour.
    Day View

    Week View

Whenever Trip Zones have been applied to a day, it will alter the view of the Account List, the one that appears when adding a new call to the diary, to conveniently show the enabled Trip Zones instead of the default A-Z letters.
To disable this feature, simply turn off all Trip Zones for that day.