if you rent a property, does pcm (per calendar month) mean that you pay on one named date per month, or that you pay exactly once every four weeks? and if it's the latter, then you would pay more than 12 payments even though you are renting for 12 months for example? (because of longer months?!?)
per calender month means you pay once in each calender month on the same date unless it is being paid by standing order and due date falls over a weekend when it will be paid following Monday