I created a calendar event for a timed ultra race, specifying the hours, and expressing my goal distance in kilometers. When I edit the event goal, I still see the goal as originally specified, but as the event summary is displayed on both the web and the App, the goal is displayed as the original numeric quantity but with mile units. Its fair to add that my default display units are imperial, but if that explains the situation then the metric quantity needs to be converted to imperial. Interestingly, the computed pace expressed in minutes per mile is correct for the original metric distance.
I suspect an athlete with metric display as default would experience the analogous situation for a race goal expressed in miles. (e.g. 8-hour race with 50 mile goal).