Zǎo Shàng Hǎo means "Good Morning" in Chinese Students and Faculty:
It is the start of the Chinese new year and Weasleys' Wizard Wheezes joke shop located at Number 93 Diagon Alley, founded by Fred and George Weasley, is putting on a magical firework display this evening at the school. Use the exit at sunset that leads to Hagrids hut and assemble on the hillside just outside the school. The Weasleys claim that they will have dragons, lions, herds of elephants and much more wonder in store for you. Exciting!! "Yǒu hǎo de yì tiān" means "Have a nice day" in Chinese. See you tonight. Exciting!!
Warmest regards,
Headmaster Dumbledore