Frosetine was a holiday where frost dragons would perform sky dances and people would watch them while enjoying food and drinks. In Demsleth's words[1]:
"Christmas, eh? Not the same ring to it as Frosetine; that was a day when White Dragons or Frost Dragons would dance through the air and everyone bundled up to watch them. You drank this delightfully hot beverage made with a Yellat and some melted butter in tea, I think."