Upvote:10
The "Established Calm" refers to the jianning (建寧) era, from the first years of the reign of Emperor Ling. The actual meaning is closer to "establishing peace".
The "Great Hall of Benign Virtue" refers to the wēndédiàn (溫德殿), a hall in the imperial palace. The name means "palace of gentle virtues".
The "full-moon ancestral rites" is a mistranslation for wangri (望日), which is the name for the 15th of the month.
This is the original sentence:
建寧二年四月望日,帝御溫德殿。
My translation would be:
On April 15th of the second year of jianning, the Emperor held court at the wēndé palace.