Hours to Aeons (h to Gyr)

1 hour equals 1.140794586×10⁻¹³ aeons (rounded).

1 hour = 1.140794586×10⁻¹³ aeons

How to convert hours to aeons

To convert hours to aeons, multiply the number of hours by 1.140794586×10⁻¹³. The factor is rounded to 10 significant digits. To go the other way, multiply aeons by 8,765,820,000,000.

aeons = hours × 1.140794586×10⁻¹³

Example: 10 hours = 1.140794586×10⁻¹² aeons.

Months and years are not constant. This site uses the average Gregorian year of 365.2425 days, so one 'year' converts to 365.2425 days, not 365; use 'common year' for exactly 365 days.

About these units

Hour (h)

Metric (SI)Current unit

60 minutes or 3,600 seconds, one twenty-fourth of a mean solar day.

Egyptian astronomers gave us the twelve. Coffin lids from about 2150 BC show the night divided into exactly 12 intervals, tied to the rising of star groups called decans, and the day was later split into 12 hours with sundials. These were seasonal hours, a twelfth of the daylight, so a summer hour was longer than a winter one. The word itself comes from Greek hora, originally any span of time, through Latin and Old French into English in the 13th century.

Equal hours of 1/24 of a day were probably first proposed by Hipparchus, and mechanical clocks made them the practical choice, since a clock showing seasonal hours had to be readjusted every morning and evening. Today the hour is exactly 3,600 seconds and is a non-SI unit accepted for use with the SI. Civil time still bends it a little: UTC hours have lasted 3,601 seconds 27 times since 1972 to keep clocks within 0.9 seconds of the Earth's rotation. In practice we use it for working shifts, travel times and electricity bills measured in kilowatt-hours.

1 hour = 3,600 seconds (exactly).

Sources: Wikipedia: Hour; BIPM: SI Brochure, 9th edition

Aeon (Gyr)

AstronomicalCurrent unit

One billion years. The Earth is about 4.5 aeons old.

Aeon comes from a Greek word meaning life, vital force, or an age, and its Latin cousin aevum lies behind English words such as eternal and medieval. In ordinary speech it means any very long, indefinite stretch. Philosophical and religious traditions use it differently, with Buddhist and Hindu texts sometimes rendering kalpa as aeon and Gnostic writers using it for divine emanations.

Astronomers fix a definite size, defining an aeon as a billion years. The figure used here is therefore 10 to the power of 9 Gregorian years, about 3.16 times 10 to the power of 16 seconds, which is a convention rather than a measured length. Geologists use the closely related spelling eon for the largest divisions of Earth's history, namely the Hadean, Archean, Proterozoic and Phanerozoic, and these are not billion-year blocks, since the Phanerozoic covers only about 538.8 million years. With Earth about 4.54 billion years old, it is roughly 4.5 aeons old.

1 aeon = 3.1556952×10¹⁶ seconds (exactly).

Sources: Wikipedia: Aeon; Wikipedia: Geologic time scale

Related conversions

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