alt Hacker NewsCool project.
I had thought that months aren't quite a human construct, they correspond roughly to lunar cycles. Weeks were a way to carve the month up into the four lunar phases per cycle.
Seconds, minutes, hours, etc. are, as you say, all sexagesimal math bias.
You're right about months/weeks, I was imprecise in the post: calendar months (as we now use them) are a weird cultural construct (I mean who would divide a measurement unevenly and though that was a good idea?)
Referencing actual phenomena would be more elegant - but wouldn't show correct date (see my comment here https://news.ycombinator.com/item?id=47686522)