The<unk> , sometimes referred to as the<unk>  phenomenon, is a perceived increase in the risk of medical errors and surgical complications that occurs in association with the time of year in which United States medical school graduates begin residencies. A similar period in the United Kingdom is known as the killing season or, more specifically, Black Wednesday, referring to the first Wednesday in August when postgraduate trainees commence their rotations.
July effect
Weekend effect
Birthday effect
Whitten effect
Widowhood effect
Lombard effect
Ceiling effect 
Martha Mitchell effect