Critical care often unfolds amid uncertainty in diagnosis, therapeutic options and prognosis. Patients frequently lack decision-making capacity, while families confront emotional distress and value conflict in surrogate choices. In this context, time-limited trials (TLTs) have been proposed as a pragmatic mechanism to limit non-beneficial treatment while allowing time for clinical clarification and moral deliberation. Despite growing operational guidance, an inclusive ethical account of TLTs remains underdeveloped. We offer a normative analysis organised across four ethical dimensions and 11 analytic categories, integrating the perspectives of patients, families and healthcare professionals and situating bedside practice within broader considerations of justice and public interest. We examine justificatory foundations, legislative and institutional preparedness, anticipated benefits and recurrent challenges. The analysis identifies pressing knowledge gaps: preference discordance; supports for anticipatory grief and bereavement; ethically coherent approaches for organ donation and systemic barriers to implementation. Addressing these gaps is essential for ethically defensible integration of TLTs across diverse healthcare systems. This framework aims to guide patient-centred, relationally attentive and distributively just decision-making while reducing moral distress and supporting the psychological well-being of families and clinicians at the end of life.