In some communities in Southern India, the onset of the period for a girl is a big event and is celebrated. Let me explain. My mom had the chat with me about getting a period and menstruation. We had sales reps from Carefree/Stayfree give us the demo on how to use a pad and gave us free samples. I was one of the last ones in my all-girls school to get a period - ninth grade @ 13.5 years!
When I told my mother, she called my grandmother. I was islolated for 3 days. I couldn't bathe, I couldn't touch anyone. I felt like a prisoner. On the fourth day, I was given a head to toe oil bath - like a Hammam! Except, it was spa day at home. I was given new clothes to wear. An auspicious day and time was set to invite all family and friends to get their blessings. It was a mini-wedding reception minus the groom. I got lots of presents and cash as gifts.
When I had to take the leave letter to school with the reason why I didn't go to school for like 5 days or so, I was embarrased to death to give that letter to my teacher. Culturally she understood why, but none of my friends had taken a week off to celebrate their first period. I didn't do any such thing with my daughter. Life just went on.
As far as mentsrual leave is concerned. I think some women have a harder time during the monthly period than others. I have friends who needed to take medication and hot compress, etc to get through the first couple of days. I on the other hand get this occasional headache but I am not as affected. So I guess, the menstrual leave can be made available and those who need it will take it. I also think those who don't need it may also be tempted to take it anyways.