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Danna (Mesopotamian)
Danna (Sumerian) or Beru (Akkadian) is a word denoting a unit of time consisting of two hours. There were twelve Danna in a day. Danna were first used around 2400 BC. Change in length and decline In Hellenistic times the Danna was halved with the introduction of the temporal hours and the number of daylight hours increased from twelve to twenty-four. The conversion was based on the ancient Egyptian precursors of the 24 seasonally - equal hours. A 24-hour division of the day could not be proven in inscriptions on Babylonian tablets, which is why the Babylonians cannot be used as the originators of the 24-hour division of the day.Vgl. Friedrich-Karl Ginzel: ''Handbuch der mathematischen und technischen Chronologie, Bd. 1 - Zeitrechnung der Babylonier, Ägypter, Mohammedaner, Perser, Inder, Südostasiaten, Chinesen, Japaner und Zentralamerikaner -'', Deutsche Buch-Ex- und Import, Leipzig 1958 (Nachdruck Leipzig 1906), S. 123. See also * Unequal hours * Equinoctial hours An equ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hellenistic Period
In Classical antiquity, the Hellenistic period covers the time in Mediterranean history after Classical Greece, between the death of Alexander the Great in 323 BC and the emergence of the Roman Empire, as signified by the Battle of Actium in 31 BC and the conquest of Ptolemaic Egypt the following year. The Ancient Greek word ''Hellas'' (, ''Hellás'') was gradually recognized as the name for Greece, from which the word ''Hellenistic'' was derived. "Hellenistic" is distinguished from "Hellenic" in that the latter refers to Greece itself, while the former encompasses all ancient territories under Greek influence, in particular the East after the conquests of Alexander the Great. After the Macedonian invasion of the Achaemenid Empire in 330 BC and its disintegration shortly after, the Hellenistic kingdoms were established throughout south-west Asia ( Seleucid Empire, Kingdom of Pergamon), north-east Africa ( Ptolemaic Kingdom) and South Asia ( Greco-Bactrian Kingdom, Indo-Greek ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temporal Hours
Unequal hours are the division of the light day and the night into 12 sections each, whatever the season. They are also called temporal hours, seasonal hours, biblical or Jewish hours, as well as ancient or Roman hours (). They are ''unequal duration'' periods of time because days are longer and nights shorter in summer than in winter. Their use in everyday life was replaced in the late Middle Ages by the now common ones of equal duration. The first temporal hour of daylight begins at Sunrise, the first of night at Sunset. For example, if daylight and night are each divided into twelve temporal hours, Midday and Midnight are each the beginning of the seventh hour. A clock that displays the temporal hours is called a temporal clock. Astronomical basics To the concept of ''light day'' corresponds the astronomical concept '' Day arc of the Sun''. With the exception of the equator, the duration of daylight depends on the latitude and the season. At 49° north/south latitud ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unequal Hours
Unequal hours are the division of the Daytime, light day and the night into 12 sections each, whatever the season. They are also called temporal hours, seasonal hours, biblical or Jewish hours, as well as ancient or Roman hours (). They are ''unequal duration'' periods of time because days are longer and nights shorter in summer than in winter. Their use in everyday life was replaced in the late Middle Ages by the now common ones of equal duration. The first temporal hour of daylight begins at Sunrise, the first of night at Sunset. For example, if daylight and night are each divided into twelve temporal hours, Noon, Midday and Midnight are each the beginning of the seventh hour. A clock that displays the temporal hours is called a temporal clock. Astronomical basics To the concept of ''light day'' corresponds the astronomical concept '':de:Tagbogen, Day arc of the Sun''. With the exception of the equator, the duration of daylight depends on the latitude and the season. At 49° ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equinoctial Hours
An equinoctial hour is one of the 24 parts of the full day consisting of light day and the night. Its length, unlike the temporal hour, ''does not'' vary with the season, but is constant. The measurement of the full day with equinoctial hours of equal length was first used about 2,400 years ago in Babylonia to make astronomical observations comparable regardless of the season. Our present hour is an equinoctial hour, freed only from its seasonal variation and from the small error due to some uniform Earth rotation, and realized by modern technical means (atomic clock, satellite and VLBI- Astrometry). With the temporal hour, the light day and night, whose lengths vary greatly throughout the year, were divided into 12 hours each. This corresponded to the earlier sentiment and custom of not grouping the night with the light day. The name ''equinoctial hours'' refers to the fact that the temporal hours of the light day and those of the dark night are of equal length a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
