Is the jinn's perception of matters, and the resulting knowledge, faster than that of humans considered knowledge of the Unseen (Ghayb), or does the Unseen have a specific time frame to be called Unseen, such as days or months?

Absolute knowledge of the Unseen belongs to Allah alone, as stated in the verse from Surat An-Naml. As for relative knowledge of the Unseen, which one person may know before another, it does not indicate a special characteristic that makes the first a partner in the attributes of Allah. So, if the jinn knew something before humans, this is knowledge of a relative unseen due to the limitations of human senses, not knowledge of the absolute Unseen.