It wasn't Sunday that she visited me, but Monday. - She visited me, not on Sunday, but on Monday.
It wasn't Sunday that she visited me, but Monday.
She visited me, not on Sunday, but on Monday.
She visited me, not on Sunday, but on Monday. - She didn't visit me on Sunday, but on Monday.
She didn't visit me on Sunday, but on Monday.
... People get excited about Mondays and Thursdays now. ...
... every Mondays and Thursdays. ...