A Fernet token has the following format:
Version ‖ Timestamp ‖ IV ‖ Ciphertext ‖ HMAC
As the above shows, the timestamp is not part of the ciphertext, so anyone can read the time the token was made. In a live stream of data this may not be a problem, but for token stored on disk, an attacker may be able to use the creation time to assist cracking. Should the timestamp be encrypted?