The expected departure time.
- iOS 9.0+
- macOS 10.11+
- tvOS 9.0+
The value of this property is dependent on whether you specified a departure date or arrival date in your
MKDirections object. If you specified a departure date, that date is copied to this property. If you specified an arrival date but not a departure date, the departure date is computed by subtracting the expected travel time from your arrival date. If you did not specify an arrival date or departure date, this property is set to the current time.