08-02-2023-0314 - DRAFT (NUCLEAR TIMESCALE)

In astrophysics, the nuclear timescale is an estimate of the lifetime of a star based solely on its rate of fuel consumption. Along with the thermal and free-fall (aka dynamical) time scales, it is used to estimate the length of time a particular star will remain in a certain phase of its life and its lifespan if hypothetical conditions are met. In reality, the lifespan of a star is greater than what is estimated by the nuclear time scale because as one fuel becomes scarce, another will generally take its place—hydrogen burning gives way to helium burning, etc. However, all the phases after hydrogen burning combined typically add up to less than 10% of the duration of hydrogen burning. 

https://en.wikipedia.org/wiki/Nuclear_timescale

08-02-2023-0313 - DRAFT (TIMEKEEPER)

From Wikipedia, the free encyclopedia

(Redirected from Time keeper)

For the Disney attraction, see The Timekeeper.

A timekeeper is an instrument or person that measures the passage of time.

Person

A timekeeper is a person who measures time with the assistance of a clock or a stopwatch. In addition, a timekeeper records time, time taken, or time remaining during events such as sports matches.

Instrument

Main article: History of timekeeping devices

A timekeeper is often referred to as a time clock, which tracks employee time. Collecting such data gives employers insight into their workforce. They can then make operational decisions to increase productivity and reduce labor costs.

See also

Look up timekeeper in Wiktionary, the free dictionary.

• Atomic clock
• Chess clock
• Fully automatic time
• Horology
• Referee
• Sense of time
• Stopwatch
• Time clock
• Timegrapher
• Timesheet
• Time tracking software

External links

• A Walk Through Time at the National Institute of Standards and Technology
• "Treatise for Observers on Constructing the Circle of Projection" is a manuscript, in Arabic, from 1473, about timekeeping.

v t e Time measurement and standards
Chronometry Orders of magnitude Metrology
International standards	Coordinated Universal Time offset UT ΔT DUT1 International Earth Rotation and Reference Systems Service ISO 31-1 ISO 8601 International Atomic Time 12-hour clock 24-hour clock Barycentric Coordinate Time Barycentric Dynamical Time Civil time Daylight saving time Geocentric Coordinate Time International Date Line IERS Reference Meridian Leap second Solar time Terrestrial Time Time zone 180th meridian
Obsolete standards	Ephemeris time Greenwich Mean Time Prime meridian
Time in physics	Absolute space and time Spacetime Chronon Continuous signal Coordinate time Cosmological decade Discrete time and continuous time Proper time Theory of relativity Time dilation Gravitational time dilation Time domain Time translation symmetry T-symmetry
Horology	Clock Astrarium Atomic clock Complication History of timekeeping devices Hourglass Marine chronometer Marine sandglass Radio clock Watch stopwatch Water clock Sundial Dialing scales Equation of time History of sundials Sundial markup schema
Calendar	Gregorian Hebrew Hindu Holocene Islamic (lunar Hijri) Julian Solar Hijri Astronomical Dominical letter Epact Equinox Intercalation Julian date Leap year Lunar Lunisolar Solar Solstice Tropical year Weekday determination Weekday names
Archaeology and geology	Chronological dating Geologic time scale International Commission on Stratigraphy
Astronomical chronology	Galactic year Nuclear timescale Precession Sidereal time
Other units of time	Instant Flick Shake Jiffy Second Minute Moment Hour Day Week Fortnight Month Year Olympiad Lustrum Decade Century Saeculum Millennium
Related topics	Chronology Duration music Mental chronometry Decimal time Metric time System time Time metrology Time value of money Timekeeper

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Categories:

• Sports occupations and roles
• Sports officiating
• Timekeeping
• Standards and measurement stubs
• Time stubs

https://en.wikipedia.org/wiki/Timekeeper

08-02-2023-0313 - DRAFT (TIME, DATE AND TIME REPRESENTATION, CHRONOLOGY)

https://en.wikipedia.org/wiki/Category:Time

https://en.wikipedia.org/wiki/Category:Date_and_time_representation

https://en.wikipedia.org/wiki/Chronology

v t e Chronology
Key topics	Archaeology Astronomy Geology History Big History Paleontology Time
Periods Eras Epochs	Calendar eras Human Era Ab urbe condita Anno Domini / Common Era Anno Mundi Bosporan era Bostran era Byzantine era Seleucid era Era of Caesar (Iberia) Before present Hijri Egyptian Sothic cycle Hindu units of time (Yuga) Mesoamerican Long Count Short Count Tzolk'in Haab' Regnal year Anka year Canon of Kings English and British regnal year Lists of kings Limmu Era names Chinese Japanese Korean Vietnamese
Calendars	Pre-Julian / Julian Pre-Julian Roman Original Julian Proleptic Julian Revised Julian Gregorian Gregorian Proleptic Gregorian Old Style and New Style dates Adoption of the Gregorian calendar Dual dating Astronomical Lunisolar (Hebrew, Hindu) Solar Lunar (Islamic) Astronomical year numbering Others Chinese sexagenary cycle Geologic Calendar Iranian ISO week date Mesoamerican Maya Aztec Winter count New Earth Time
Astronomic time	Cosmic Calendar Ephemeris Galactic year Metonic cycle Milankovitch cycles
Geologic time	Concepts Deep time Geological history of Earth Geological time units Standards Global Standard Stratigraphic Age (GSSA) Global Boundary Stratotype Section and Point (GSSP) Methods Chronostratigraphy Geochronology Isotope geochemistry Law of superposition Luminescence dating Samarium–neodymium dating
Chronological dating	Absolute dating Amino acid racemisation Archaeomagnetic dating Dendrochronology Ice core Incremental dating Lichenometry Paleomagnetism Radiometric dating Lead–lead Potassium–argon Radiocarbon Uranium–lead Tephrochronology Luminescence dating Thermoluminescence dating Relative dating Fluorine absorption Nitrogen dating Obsidian hydration Seriation Stratigraphy
Genetic methods	Molecular clock
Linguistic methods	Glottochronology
Related topics	Chronicle New Chronology Synchronoptic view Timeline Year zero Floruit Terminus post quem ASPRO chronology

Authority control

Categories:

• Chronology
• Earth sciences
• Time

Time
Key concepts	Past Present Future Eternity
Measurement and standards	Chronometry UTC UT TAI Unit of time Orders of magnitude (time) Measurement systems Italian six-hour clock Thai six-hour clock 12-hour clock 24-hour clock Relative hour Daylight saving time Chinese Decimal Hexadecimal Hindu Metric Roman Sidereal Solar Time zone Calendars Main types Solar Lunar Lunisolar Gregorian Julian Hebrew Islamic Solar Hijri Chinese Hindu Panchang Maya List Clocks Main types astronomical astrarium atomic quantum hourglass marine sundial watch mechanical stopwatch water-based Cuckoo clock Digital clock Grandfather clock History Timeline
Chronology History	Astronomical chronology Big History Calendar era Deep time Periodization Regnal year Timeline
Philosophy of time	A series and B series B-theory of time Chronocentrism Duration Endurantism Eternal return Eternalism Event Perdurantism Presentism Temporal finitism Temporal parts The Unreality of Time
Religion Mythology	Ages of Man Destiny Immortality Dreamtime Kāla Time and fate deities Father Time Wheel of time Kalachakra
Human experience and use of time	Chronemics Generation time Mental chronometry Music tempo time signature Rosy retrospection Tense–aspect–mood Time discipline Time management Yesterday – Today – Tomorrow
Time in science	Geology Geological time age chron eon epoch era period Geochronology Geological history of Earth Physics Absolute space and time Arrow of time Chronon Coordinate time Instant Proper time Spacetime Theory of relativity Time domain Time translation symmetry Time reversal symmetry Other fields Chronological dating Chronobiology Circadian rhythms Clock reaction Glottochronology Time geography
Related	Memory Moment Space System time Tempus fugit Time capsule Time immemorial Time travel
Category Commons https://en.wikipedia.org/wiki/Chronology