According to official website information of Huangshan Cultural Tourism Bureau, tickets for Huangshan Scenic Area are only valid on the same day. If you don't use them within the time limit, please apply for cancellation within 7 days. At the same time, during the ticket booking period, you can use the "Huangshan Tickets-Free Tickets" function of "Huangshan Tourism Official Platform" to make an appointment for the corresponding free tickets.
If you miss the booking time for various reasons, you need to consult a tour guide or explain the situation directly to the staff of the scenic spot. If you make an appointment and pay, they may let you in.
Generally speaking, the booking system of Huangshan tickets is to control the number of tourists, avoid overcrowding in scenic spots, and ensure the tourist experience and the sustainable development of scenic spots. Therefore, I suggest that you plan your trip in advance and make an appointment for tickets on time before going to Huangshan.