365 day calendar

As I understand it the Babylonians had a 365-day year, although they used a lunar calendar in normal life. In fact pretty good calculations of the year length turn up very early in the history of civilisation; what seems to bog so many cultures down is that the numbers are messy and and cannot be neatly divided into one another, which probably drove the specialists to a frenzy of frustration, becuase none of the solutions were "neat".