9536 1502 What does it mean to board the plane by Shenzhen Airlines?

9536 1502 Shenzhen Airlines sends boarding information, which means to remind users to board the plane on time and not to miss the plane. It's a SMS reminder from Shenzhen Airlines. It is best to arrive at the airport 1 hour before departure. Generally, the security check-in starts 2 hours before the flight departure time (3 hours in advance for larger airports), and the check-in procedure stops 45 minutes before the flight departure time.