Wave asked:
Or would the histogram have peaks and valleys according to the season or some other time dependent variable such as the school calendar, holidays or basic weather patterns?
I was hoping to hear of solid data that repeats according to the calendar.
Before modern times, the church required fasting and sexual abstinence many times a year. I’ve wondered if this was calculated to harmonize the seasons, harvests and planting with child birth.

Certainly it would vary.
There are many instances of birth booms occurring 9 months after large scale blackouts and blizzards.
Certainly there is variation. Think about it. Would you like to be heavy with child during the hottest months of the summer?
They say there are more births during a full moon than any other time. I’ve heard this from nurses & doctors that work in hospital maternity floors.