Did you know that menstruation may have led to humanity’s sense of time? This 28-days cycle, which at one point of time in the history was considered gross, could have been responsible for the division of time and days that we know in the present day.
Most early lunar calendars were based on the length of a woman’s menstrual cycle. A woman’s cycle and the lunation cycle (moon phases) are the same cycle. Women ovulated when the moon was full, and bled when the moon was dark. Menstruating women were strongly associated with mystery, magic, and even sorcery.
Though females have experienced menstruation since before humans even fully evolved as a species, there is very little documentation about periods among ancient people. You must have noticed your grandmother and even mother for that matter, using the word “maheena” for denoting periods. It is quite a possibility that the observation of menstrual cycle has served as an aid to the knowledge of time.