@xepia_ @MelissaBearTrix

There's a post on here somewhere, about a professor talking to her students. She shows them a photo of a bone with 28 marks carved into it. She asks them if they think it was man's first attempt at a calendar. They agree. Then she says it was probably woman's first attempt at a calendar. Why? She asks them if a man, or a woman, would have a greater need to keep track of 28 days.