If the event is just 2 hours long, keep the intro and the closing short. If you spend 2.5 hours or more, you can spend more time on the closing. If the event is even longer, consider running something by the middle of it, to give people a moment to step away from the project.
Pro un evento de duo horas, mantene breve le introduction e le clausura. Si le durata es 2,5 horas o plus, tu pote dedicar plus tempore al clausura. Si le evento es mesmo plus longe, considera de organisar un activitate intermediari como pausa pro le participantes.