The graphic is disgusting, but it might be nice if women wore a T-shirt with a warning stating “It’s that time of the month” or something.
There's an app for that. Really. I know the guy who wrote it. It keeps a database of the guys friends. If he gets tickets for a concert, he can tell who will be the best candidates. He sells the app in about 20 languages now.
He did a presentation on his app once at a developers' meeting. He didn't tell what the app does, but explained how its constructed, how he developed it, how he marketed it, how it keeps a 28 day calendar that can be customized for each woman in the DB . You could tell when individuals in the audience finally figured out what the app does.