I apologize if the similar topic is brought out already.

In order to quality for Elite Card, I'd need 40,000 status miles within 12 consecutive months.

This means, suppose I accumulated miles starting 15/May/2016, I need to cross 40,000 status miles by 14/May/2016? Or if counting month-wise, it means I have to have them by 30/Apr/2016? A bit confused by the definition.