That is what I assumed the scenario duration was, but in the instance where I only got to drive for ~2 minutes, it ended with 'scenario completed', meaning there's likely some issues with the calculation of the remaining duration.
As for timezones, my problem is that the time at the top of the main menu and the server dispatch times are using different timezones (since I am in CET and there are no servers based within that timezone). That being said, if the scenario duration shows how long is left, the departure time is almost irrelevant.