Nursing staff are the largest group of professionals in the health care team that provides 24-hr patient care across a 7-day workweek. The provision of most nursing care inevitably involves irregular hours, and more recently, nurses tend to work longer shifts (Rhéaume & Mullen, 2018). A 12-hr shift, which is now common for staff nurses, actually requires nurses to be in the workplace for more than 13 hr, due to extra tasks such as paperwork (Rhéaume & Mullen, 2018;Trinkoff et al., 2006). However, one advantage of a 12-hr shift system for nurses is to have more free time: it is not unusual to have 3 or 4 days off per week.There is, however, growing concern about the impact of shift work and long working hours on nurses' health and on patient outcomes (Chaiard et al., 2018;Ferri et al., 2016;Rhéaume & Mullen, 2018). Thus, adverse health effects of shift work have been widely studied and documented in the literature; circadian rhythm disorder, fatigue, obesity, impaired sleep quality and quantity (Choobineh et al., 2012;Jafari Roodbandi et al., 2015), and a wide range of chronic diseases can lead to more sick leave and