Survival to discharge in patients who experienced in-hospital cardiac arrest during "off-hours" was an absolute 3.8% lower than patients who arrested during "on-hours," according to a study published January 22, 2018 in the Journal of the American College of Cardiology. On-hours was categorized as 7:00 a.m. to 10:59 p.m. Monday to Friday. Off-hours was described as 11:00 p.m. to 6:59 a.m. Monday to Friday or anytime on weekends.