Civil day
From Glossary of Meteorology
civil day
A mean solar day reckoned from midnight to midnight, usually divided into two 12- hour divisions, although now often regarded as a single 24-hour series.
As practically applied by use of meridional time zones of approximately 15° width, civil time is accurate (relative to mean solar time) to within ±30 minutes, or 7½° of longitude. Minor exceptions occur when the time zones have been established according to geopolitical considerations, rather than adhering strictly to the meridians.
See apparent solar day, day.
See apparent solar day, day.
