What does it mean to open He Lv Palace in nine days?

The nine gates of heaven reveal the palace and its courtyard, which means that all the palaces, palaces and halls have opened their doors;

From Wang Wei's The Early Palace of Daming Palace and the Work of Jia Zhi's Scheeren.

Original text:

Wearing a red scarf, the official seal in his hand rose to dawn, and the official was changed to Emperor Cui Yunzuo.

Nine palaces opened the Golden Palace, and envoys from all countries bowed to the emperor.

At the beginning of the day, Sun shook his palm and smoked a yellow robe.

At the end of the early years, to write an imperial edict to the emperor, Yu Pei Yudingdang returned to the Phoenix Pool.

Translation:

The guards wore red scarves, sang like cocks and reported the dawn. The official in charge of royal service has just brought Cui into court. Many deep palaces, forbidden gardens and halls have opened their doors; Under the emperor's orders, officials and guests paid tribute to the emperor. The barrier fan that blocks the sun is moved forward by the morning light; The light smoke from the incense burner rose beside the emperor's robe. After the pilgrimage, Jia she drafted letters with five-color paper; You can hear the clang of clothes. He has returned to Zhongshu Province.