Whilst the nature of human illness is not determined by time of day or day of week, we currently structure health service delivery around a five-day delivery model. At least one country is endeavouring to develop a systems-based approach to planning a transition from five- to seven-day healthcare delivery models, and some services are independently instituting program reorganization to achieve these ends as research, amongst other things, highlights increased mortality and morbidity for weekend and after-hours admissions to hospitals. In this (...) article, we argue that this issue does not merely raise instrumental concerns but also opens up a normative ethical dimension, recognizing that clinical ethical dilemmas are impacted on and created by systems of care. Using health policy ethics, we critically examine whether our health services, as currently structured, are at odds with ethical obligations for patient care and broader collective goals associated with the provision of publicly funded health services. We conclude by arguing that a critical health policy ethics perspective applying relevant ethical values and principles needs to be included when considering whether and how to transition from five-day to seven-day models for health delivery. (shrink)