Atomic clock — ultra-precise timekeeping using atomic transitions Atomic clock A clock that uses the natural frequency of atomic energy transitions as its timekeeping reference; the basis of modern time standards, navigation, telecom and precision science.
Bell tower (belfry, campanile): structure, history, and uses Bell tower A bell tower—also called a belfry or campanile—is a tower built to house bells for timekeeping, worship, signaling, and music. This article explains design, ringing methods, histor…
Bengali calendar (Bangla calendar) Bengali calendar A solar calendar used in Bengal and officially in Bangladesh; organizes the year into twelve months and six seasons, and marks Pohela Boishakh as the New Year in mid-April.
Calendar date — definition, components, history and uses Calendar date A calendar date names a particular day within a given calendar system. This article explains its parts, formats, historical development, uses, and why the same date can mean differ…
International Date Line Imaginary line near the 180° meridian where the calendar date changes by one day when crossed; it deviates to follow national borders and islands.
