Nyx is the goddess of the night, but her lucky Star offers you the opportunity to wake up your horse at 6 AM instead of 8 AM. With this star, you can still put your horse to bed at 10 PM without damaging its energy or health for the next day.
You can take care of him more and make him progress faster.
Nyx's Star is a privilege. To get it, you have to use Nyx's Pack.