34. Many a moon

In addition to mathematical procedures, the dating of eclipses in Babylonian records requires a workable contemporary calendar.

The seminal work was completed half a century ago, and subsequent improvements have been rare. The study determined the placement of intercalary (leap) months in the Babylonian calendar, and then linked the first day of every month to a Julian calendar date.

As a bonus, the authors assembled the available evidence for the beginning of every reign from 626 BC to AD 75, in effect providing a Babylonian chronology of the period.