døgnklokke

Døgnklokke is a timekeeping system that displays time along a 24-hour scale, rather than the 12-hour cycle with AM and PM. In this system, the day runs from 00:00 to 23:59, with 00:00 marking midnight and 12:00 noon. The term is used in Norwegian to describe clocks that show 24-hour time and written time formats in public timetables, schedules, and official documents.

Origins and use: The 24-hour clock has historical roots in astronomical timekeeping and is widely used in military, aviation, computing, and public transport. In Norway and many European countries, døgnklokke is standard in timetables, hospitals, and workplaces.

Notation and format: Times are written as HH:mm, with leading zeros for single-digit hours (e.g., 03:07). In many contexts, seconds may be appended as HH:mm:ss. The 24-hour format avoids the ambiguity between morning and afternoon that can occur with the 12-hour clock.

Advantages and challenges: The 24-hour clock reduces confusion in scheduling and data processing and aligns with ISO 8601 representations. It can be more efficient for digital systems. The main challenge is that some people find it less intuitive for casual or domestic use, requiring mental conversion for those accustomed to 12-hour notation.

See also: 24-hour clock; military time; ISO 8601.