Venus tablet of Ammisaduqa

The Venus tablet of Ammisaduqa is the record of astronomical observations of Venus. It is preserved in many cuneiform tablets from the first millennium BC. 
This astronomical record was probably first done during the reign of King Ammisaduqa (or Ammizaduga). He was the fourth ruler after Hammurabi. So, the origins of this text should be dated to around the mid-seventeenth century BC.
The tablet recorded the rise times of Venus and its first and last visibility on the horizon before or after sunrise and sunset. It records these as lunar dates. These observations are recorded for 21 years.