You forgot the "7*" before 24 hours. Which translates to a week before fast passes expire.
That said, I'm not happy with the change either. With the current system, free readers can earn a grand total of 5 coins per day.
This means that any free reader that saved up SS (now coins) to purchase a privilege for his/her favorite novel here is almost guaranteed not to be able to make the most out of the privilege they saved up for.