I took it on Sun. morning, around 11am, leaving the Naples Central Train Station going to Capo and it was running. I am not sure how early on Sun. it starts running, but I think pretty early. Here is a link to some info. on Capo airport site, http://www.portal.gesac.it/portal/page/portal/internet/inAEROPORTO/Autobus, it gives the link to ANM that you can put into Google translate if you need to.