Be prepared to manage the webinar timing
We are all guilty of losing track of time, especially when we get talking passionately about something. Therefore, it is highly likely that your presenters will not be monitoring the time as they are presenting, so it is up to you as the Moderator to manage this for them.
Now, most webinar providers will not cut you off or chastise you for going over the allotted time. However, those that have signed up to the event may have other appointments they need to get to so try and keep within the allotted time.
Mostly, ensure that the core presentations have been done and if you are going to run over it will just be questions and answers, so those that have to leave bang on time do not feel short changed.