High-latitude environments subject residents to extreme seasonal variations in light. This qualitative study examined how civilians living at high northern latitudes experience and manage sleep, mood and time across winter darkness and summer light. Twenty-eight adults residing in Scandinavia, Estonia and Canada completed an in-depth online, open-ended survey. Using reflexive thematic analysis, we identified a lived ecology of seasonal strain spanning physiology, emotion and temporal experience. Participants described winter as heavier sleep with difficult awakenings, inertia and flatter affect and summer as shallow, fractured sleep and a “wired” restlessness. Evening-type (“night-owl”) individuals reported greater strain across both seasons: winter mornings felt biologically unworkable, whereas summer nights never properly “started.” Crucially, people also reported changes in how they experienced time itself. Under unstable photoperiods, “day” and “night” became things to make rather than to feel: weeks “blurred” without deliberate anchors, prompting intentional “temporal scaffolds” such as fixed wake times and mealtimes, blackout in summer, morning light in winter, seasonal rituals, scheduled outdoor exposure, and, for some, temporary relocation. We interpret these accounts within circadian alignment and social zeitgeber frameworks and extend them by specifying temporal experience, not just sleep or mood, as a key outcome of environmental light. Implications include chronotype-aware screening in primary care, normalising circadian and temporal hygiene in public messaging, and embedding light scheduling and routine-based supports within fatigue-risk management for isolated, confined and extreme operations. The findings provide an ecological description of civilian adaptation at high latitude and generate testable predictions for future quantitative and operational studies.