This article is from the Lure Coursing FAQ, by Bonnie Dalzell with numerous contributions by others.
From roll call to the completion of the trial. Be prepared for a long
day, especially in bad weather. Bring plenty of food and water. Bring
warm clothing and wet weather gear. In hot weather bring shade.
A club can usually complete an all breed trial of 30 hounds in 5
hours. I have seen 30 hound specialty trials (one breed) be run in 3
hours. However trials with small entries are often run at a leisurely
pace and may take until dusk, while trials with large entries will be
pushed along by the certain knowledge that they must be completed
before dusk. Either way it adds up to a looong day.