Striking clockA striking clock is a clock that sounds the hours audibly on a bell, gong, or other audible device. In 12-hour striking, used most commonly in striking clocks today, the clock strikes once at 1:00 am, twice at 2:00 am, continuing in this way up to twelve times at 12:00 mid-day, then starts again, striking once at 1:00pm, twice at 2:00 pm, up to twelve times at 12:00 midnight. The striking feature of clocks was originally more important than their clock faces; the earliest clocks struck the hours, but had no dials to enable the time to be read.
Philosophical presentismPhilosophical presentism is the view that only present entities exist (or, equivalently, that everything is present). According to presentism, there are no past or future entities. In a sense, the past and the future do not exist for presentists—past events have happened (have existed) and future events will happen (will exist), but neither exist at all since they do not exist now.
B-theory of timeThe B-theory of time, also called the "tenseless theory of time", is one of two positions regarding the temporal ordering of events in the philosophy of time. B-theorists argue that the flow of time is only a subjective illusion of human consciousness, that the past, present, and future are equally real, and that time is tenseless: temporal becoming is not an objective feature of reality. Therefore, there is nothing privileged about the present, ontologically speaking. The B-theory is derived from a distinction drawn by J.
Specious presentThe specious present is the time duration wherein one's perceptions are considered to be in the present. Time perception studies the sense of time, which differs from other senses since time cannot be directly perceived but must be reconstructed by the brain. The term was coined by E. Robert Kelly, better known under the pseudonym "E. R. Clay". The relation of experience to time has not been profoundly studied.
ChronometryChronometry (from Greek χρόνος chronos, "time" and μέτρον metron, "measure") is the science of the measurement of time, or timekeeping. Chronometry provides a standard of measurement for time, and therefore serves as a significant reference for many and various fields of science. The importance of the accuracy and reliability of measuring time provides a standardized unit for chronometric experiments for the modern world, and more specifically scientific research.
24-hour clockThe modern 24-hour clock, popularly referred to in the United States as military time, is the convention of timekeeping in which the day runs from midnight to midnight and is divided into 24 hours. This is indicated by the hours (and minutes) passed since midnight, from 0(:00) to 23(:59). This system, as opposed to the 12-hour clock, is the most commonly used time notation in the world today, and is used by the international standard ISO 8601. A number of countries, particularly English-speaking, use the 12-hour clock, or a mixture of the 24- and 12-hour time systems.
Time managementTime management is the process of planning and exercising conscious control of time spent on specific activities - especially to increase effectiveness, efficiency, and productivity. It involves of various demands upon a person relating to work, social life, family, hobbies, personal interests, and commitments with the finite nature of time. Using time effectively gives the person "choice" on spending or managing activities at their own time and expediency.
HorologyHorology (the study of time; related to Latin horologium; ; , interfix -o-, and suffix -logy) is the study of the measurement of time. Clocks, watches, clockwork, sundials, hourglasses, clepsydras, timers, time recorders, marine chronometers, and atomic clocks are all examples of instruments used to measure time. In current usage, horology refers mainly to the study of mechanical time-keeping devices, while chronometry more broadly includes electronic devices that have largely supplanted mechanical clocks for the best accuracy and precision in time-keeping.
Barycentric Coordinate TimeBarycentric Coordinate Time (TCB, from the French Temps-coordonnée barycentrique) is a coordinate time standard intended to be used as the independent variable of time for all calculations pertaining to orbits of planets, asteroids, comets, and interplanetary spacecraft in the Solar System. It is equivalent to the proper time experienced by a clock at rest in a coordinate frame co-moving with the barycenter (center of mass) of the Solar System: that is, a clock that performs exactly the same movements as the Solar System but is outside the system's gravity well.
Unit of timeA unit of time is any particular time interval, used as a standard way of measuring or expressing duration. The base unit of time in the International System of Units (SI), and by extension most of the Western world, is the second, defined as about 9 billion oscillations of the caesium atom. The exact modern SI definition is "[The second] is defined by taking the fixed numerical value of the cesium frequency, ΔνCs, the unperturbed ground-state hyperfine transition frequency of the cesium 133 atom, to be 9 192 631 770 when expressed in the unit Hz, which is equal to s−1.
