Don Yan Zhenqing.

Every day when the cock crows, it is the best time for boys to read.

Teenagers only know how to play, but don't know how to study hard. When they are old, they regret why they didn't know how to study hard when they were young.

Translation:

Hard-working people, hard-working students, still working and studying at midnight.

The light is still on at midnight. After turning off the lights and lying down for a short rest, the chickens crow at the fifth watch, and these hardworking people have to get up and be busy again. If you don't know how to study hard when you are young, it will be too late to study when you are old.

Brief introduction of the author

Yan Zhenqing (August 23, 709-784), whose real name is posthumous title Xian, alias, was born in Wanzhao, Jingzhao (now Shaanxi), and his ancestral home was Lang Xun (now Shandong). Yan Shigu V was a famous minister and outstanding calligrapher in Tang Dynasty. In the 22nd year of Kaiyuan (734), Yan Zhenqing was a Jinshi, who was appointed as the censor and moved to the palace to assist the censor.