Boys born in summer and girls in winter?

So I had a friend tell me that girls are mostly always born in the winters and boys in the summer. Something to do with conception and ions. I heard that it's easier to conceive boys in the fall because they're hardier and girls are more delicate so they're conceived in the spring. Do you think there's any truth to it? Was it right for you? For myself personally it's incorrect...I have a son in July and daughter in August. Some people truly believe this though!!