I am on page 129 of 351 in The Romance of the Calendar by P.W. Wilson (1937). Before I continue I’d like to point out that Wilson missed a glorious opportunity. There should have been 14 more pages. What a laugh that would have been!
To paraphrase the first section of the book, stop and think what life might have been like before the calendar. Any calendar. Consider the uncertainty, and the regularity, of seasons, days, the stars and the moons. How would you know when to plant? When to gather wood for winter? How would you know what days to keep for worship and remembrance? How would you mark the passing of time?
You have two choices: The moon and the sun. That is, you can base your calendar on lunar cycles, or solar cycles. Which to choose?
The historical landscape, strewn with calendars, may thus be described as a vast battlefield. Everywhere there was raging a direct conflict– a warfare in the heavens– between the sun and the moon as an authority over the calendar.
We must follow this struggle between sun and moon in two major campaigns. The earlier of these campaigns may be described as Babylon versus Egypt. The latter.. as Greece versus Rome. In both of the campaigns, the moon first held the field. In both of the campaigns the sun ultimately triumphed.