Jīntiān shì Bā-Yī Jiànjūnjié, jiēshàng guàmǎn le hóngqí.
Today is Army Day, and the streets are hung with red flags.
Tips
history
It marks 1 August 1927, when Communist troops rose against the Nationalists in the 南昌起义 (Nanchang Uprising). The PLA counts that day as its founding, which is why 八一 appears on its flag and badges.
usage
Usually shortened to 建军节 or just 八一. It is not a day off for everyone: only serving soldiers get a half day.