Who is The Morrow Days. from Sir Thursday and what is their importance?

The Morrow Days are the Trustees of the Keys and Will of the Architect. The Morrow Days have gone rogue and are not being good trustees of the powers they have been given. They are: Mister Monday, Grim Tuesday, Drowned Wednesday, Sir Thursday, Lady Friday, Superior Saturday and Lord Sunday. Each corresponds with one of the Seven Deadly Sins.