Ticket Available from Nanjing to Jiuhuashan

Hi, I will be arriving NJ at 5pm and will try to purchase a bus ticket to Jiuhuashan for 7am next day. Can I know whether it is possible to get the ticket or i have to ask somebody to help me buy beforehand? I will be going to Jiuhuashan on a sunday morning so I am afraid I might not be able to get the ticket.

Thanks.