“Tell me," she continued, "what man needs to know when 28 days have passed? I suspect that this is woman's first attempt at a calendar.”
Referencing ‘The Ishango Bone’, the fibula of a baboon that is more than 22,000-28,000 years old. Discovered in the Congo region in 1957 it is something that historians and archaeologists can only really theorize on, as there is no conclusive way to prove which of the sexes created the calendar.
However there is something that tugs at my heartstrings at believing a Paleolithic woman was tracking her cycle in the same way as I do, centuries later.