What is the latest time a final round of an audition could possibly go until, if one full day was allotted for the finals in advance? I need to take a flight out the night of a final round to make something by the next morning.
I know each orchestra is different so just getting an idea of an average or others' extreme experiences, all the ones I've experienced/seen have been around late afternoon at worst.
I have personally been dismissed once after 11 PM and hired once after 10 PM. If I have a tight schedule I will generally make a backup travel plan and/or book with an airline like Southwest which will let me change my flight at no additional cost.
If there's a dedicated day for finals, that doesn't guarantee it will conclude early. It's possible that due to their working schedule or venue restrictions they will start in the late afternoon or evening. It's always a good idea to check with the personnel manager in advance.