This graph gathers around 39.5 millions of birth dates of French citizens from 1968 to 2018. The number of births for each day since 1968 are collected by INSEE, the French National Institute of Statistics and Economic Studies and the data are available on this page (the dataset is here). Then, inspired by this gist I computed the phase of the moon for each day since 1968 .
I made this graph using Python 3.6 and the repo is available here.
This idea comes from the great French Youtube Channel Hygiène Mentale.
(published in reddit)