A month on a calendar is an averag of 4 weeks. So is the woman's "cycle" of menstration/ovulation. Coincidence?

by rainydaybear

As the title states, an average cycle in a woman's period is 4 weeks, so is an average month. Is this a coincidence when the calendar was created?

SlothOfDoom

Months are based on the lunar cycle (29.53 days). Coincidentally the menstruation period in humans is of a similar length (averaging about 28 days).

There have been numerous attempts to tie the two cycles together scientifically, but none of any merit as far as I know.

To be honest, I think you might find more experts in /r/askscience unless you want to know about historic menstruation rituals and taboos of various cultures throughout history.