proleptic

This article explains the concept of chronology; for the rhetorical-narrative method of anticipating topics that were developed later, see Proleptics .

Proleptic (from ancient Greek προληπτικός prolēptikós , German 'anticipating, anticipating' ) means in the calculation of time (chronology) that a time system goes back to the past beyond its defined zero point .

The standard time measuring system of astronomy as well as chronology is the Julian date , which despite the date 0.0 on January 1st −4712 ( 4713 BC ) 12:00 is a non-proleptic decimal time system that addresses the problems of proleptic dating in Bridged the form of a uniformly continuous time scale.

Proleptic Calendar

A calendar system has a specific reference date , the epoch on which the year counting begins. All dates before this day, given in this calendar system, are then called proleptically dated . They have negative years or are described with “before the calendar” and similar terms.

See: v. BC (before the birth of Christ), ante christum natum (AC, "before the birth of Christ", also BC, before Christ ), vd Z. (before the calendar)

Not proleptic calendar

The Gregorian calendar is rarely used proleptically, with the result that there is still a "fragmented" calendar: Julian up to and including October 4, 1582, Gregorian since October 15, 1582. The ten calendar days in between have at least in Rome , Italy , Spain and Portugal historically never existed. In other countries - depending on the introduction date - there were 10 to 13 other calendar days that never existed. The Gregorian calendar is proleptically made possible by the international standard for dates and times ISO 8601 and is used in software.

Another classic dating problem is the so-called confused year 708 a. u. c. , in which the Roman calendar was changed to the Julian calendar, and its unsecured proleptic backdating at the time.

Furthermore , all calendar systems that are built on a system of ages ( era ) are not used proleptically , especially all dynastic calendar systems . The year counting starts anew at each epoch (beginning of an era), but earlier dates are given in relation to the epoch valid at that time. Examples: Egyptian calendar , Chinese calendar , Japanese calendar with Nengo , Maya calendar .

Likewise, the Islamic calendar (both lunar and Iranian / solar), which begins with the year of the hijra of the prophet Mohammed to Medina in 622 AD, is not proleptic.

The French revolutionary calendar was also not proleptic. It came into force on the 4th Frimaire II (November 24, 1793) - retroactive to the 1st Vendémiaire I (September 22, 1792, the equinox date after the proclamation of the First French Republic the day before). The dating of the Gregorian calendar was still used for the time before this original date.

On the problem of dating

The conversion of historical time and calendar systems into Julian dates is based on a more or less complicated set of formulas, depending on the system, which is built up on the basis of historical key data: Historical dates (information about date and time of day) are because it continues until the late 20th century did not give a globally binding, currently available reference about simultaneity, only traditional assignments that have to be compared with other simultaneous events based on the sources. Typical key data are, for example, astronomical events (such as solar eclipses), which can be dated with sufficient precision based on today's computer models ( astronomical chronology ) and thus provide a basis for converting Gregorian proleptic data into today's time scale.

See also

• List of calendar systems

literature

• Ludwig Rohner: Calendar History and Calendar. Academic Publishing Company Athenaion, Wiesbaden 1978, ISBN 3-7997-0692-5 .
• Heinz Zemanek : Calendar and Chronology. Known & unknown from calendar science. 6th completely revised edition. R. Oldenbourg, Munich 2008, ISBN 978-3-486-22795-6 .

Individual evidence

1. ^ Wilhelm Pape , Max Sengebusch (arrangement): Concise dictionary of the Greek language . 3rd edition, 6th impression. Vieweg & Sohn, Braunschweig 1914 ( zeno.org [accessed December 3, 2018]).
2. ↑ datetime - Basic date and time types. In: The Python Standard Library. Accessed March 28, 2019 .