Wang Zijin, an expert on the history of Qin and Han (206 BC-AD 220) dynasties, says the use of zhiri embodied ancient people's understanding of time, and their awareness and skills of time management.

It reflected social order and was seen as being related to administrative efficiency, he says.

The experts were addressing an academic symposium on zhiri at Wuhan University in early January, during which paper copies of these zhiri items were launched as the first volume of Bamboo Slips and Tablets of Shuihudi Western Han Tomb.

Over the past 50 years, dozens of Qin and Han dynasties tombs have been discovered in Shuihudi. From Yueren's tomb alone — archaeologists have labeled it Shuihudi Tomb M77 — more than 2,000 bamboo slips and wooden tablets written from 175 to 157 BC have been unearthed.

Apart from zhiri, the manuscripts also include content regarding math and law, as well as judicial documents on grain transport along the Yellow River.

The center intends to publish eight volumes of Bamboo Slips and Tablets of Shuihudi Western Han Tomb altogether to provide comprehensive information about the relics.

Qin Zhihua, head of the Zhongxi Book Co, the publisher of the series, says hopefully two more volumes will be released this year.

Experts estimate that Yueren's zhiri documents should have comprised around 900 slips, yet only about 700 have been discovered, apart from some that are damaged.