Looking at dictionary translations, it seems "to last" or "to take (in reference to time)" are both good translations into English. So "hoelang duurt een jaar?" would probably best be translated at "how long does a year last?"
You even used both of those word in your translation, I don't know why you'd say there isn't a word for it in English.
¡ Claro que sí ! In French we also have the verb "durer" in the same idea ^^