Hour: Definition

HOUR definition: 1. a period of 60 minutes: 2. one, two, etc. hours from now: 3. the period of time when a…. Learn more. The meaning of HOUR is a time or office for daily liturgical devotion; especially : canonical hour. How to use hour in a sentence. hour, in timekeeping, 3,600 seconds, now defined in terms of radiation emitted from atoms of the element cesium under specified conditions. The hour was formerly defined as the 24th part of a mean solar day — i.e., of the average period of rotation of the Earth relative to the Sun. The hour of sidereal time, 1/24 of the Earth’s rotation period relative to the stars, was about 10 seconds shorter than the hour of mean solar time. Set a timer for 2 hour with the 2 hour countdown timer with an alarm. What Is the 2 Hour Timer? This 2 hour timer helps you stay focused on tasks that last up to 2 hours.