There's another story in this trilogy which I will post soon. I am also in the process of writing a longer story set at the beginning of the Ninth Pass on Pern, which involves some of the same characters (and a few new ones as well), which I will also be posting on this site.
The Pernese word for year is indeed a Turn. It's capitalised in the books, I think to differentiate it's usage as a period of time from other uses of the same word. According to 'The Dragonlovers Guide to Pern', a Turn is 366 days, plus two days left over for the Turn's End celebrations.