The fight director should discuss possible lighting, set, direction, costume and stage management problems with the appropriate departments. If it is a long tour, the fight director may also wish to catch up with the fights, at some point during the run, and re-rehearse sections which are untidy. A fight is defined as a specialised performance involving two or more people using fists, implements or weapons, which requires choreography and supervision for safety. At the higher end of the pay scale, the fight director will be present at all rehearsals, meetings etc. This time scale is a generalisation of course.
Many factors enter into it.
But 12 hours is a good period of time to aim for. A scuffle with fists will not take as much time as Cyrano De Bergerac, but if the actors are inexperienced it could take time just to get through the basics. Similarly a full flung version of Macbeth could take many many more hours. Certainly there is no legal reason to do so, however, it is advisable to use a professional fight director on a production for two clear reasons. To make the fight good.