DayEveningNight

DayEveningNight is a conceptual framework used to divide the 24-hour day into three successive phases: day, evening, and night. The term is descriptive rather than standardized and is used across different domains to organize activities, environments, or data by time of day. Because the boundaries between these phases vary with latitude, season, and cultural norms, the exact start and end times for each phase are not fixed and may be defined by context or application.

Day is typically characterized by daylight, higher solar elevation, and peak human activity in many settings. In planning and design, Day often corresponds to periods with natural lighting and higher energy use. Evening marks the transition to lower light, civil twilight, and a shift in social routines toward rest or leisure. In lighting design, Evening phases may prompt gradual adjustments to artificial lighting. Night features darkness, lower ambient light, and reduced outdoor activity; in many contexts it warrants increased security, energy savings, and different data collection parameters.

Applications of DayEveningNight span multiple fields. In urban planning, the framework informs street lighting schedules and traffic management. In photography and cinematography, similar partitions guide exposure and white balance choices, while in software interfaces, time-based theming may switch between Day, Evening, and Night styles. In data analysis, DayEveningNight can segment metrics by typical human behavior, energy demand, or environmental conditions.

See also: circadian rhythm, twilight, blue hour, lighting design, time of day, seasonal variation.