modified Julian day

modified Julian day
(MJD)
   a count of days used by astronomers, space agencies, and others. Astronomers have long used the Julian day, a count of days beginning at noon Universal Time January 1, 4713 BC, as a means of specifying a date independent of all calendars. One problem with this is that the numbers are large, more than 2.4 million, for current dates. Also, the old astronomical custom of beginning a day at noon is awkward for converting Julian dates to the ordinary calendar. To ease these problems, space engineers introduced the modified Julian date, equal to the Julian date minus 2 400 000.5. The result is a count of days beginning at 0 hours (midnight) Universal Time on 17 November 1858. Thus (for example) 0 hours 1 January 2005 is MJD 53371.0.

Dictionary of units of measurement. 2015.

Игры ⚽ Поможем решить контрольную работу

Look at other dictionaries:

  • Julian day — JDN redirects here. For the military IT system, see Joint Data Network. For the comic book character Julian Gregory Day, see Calendar Man. Not to be confused with Julian year (disambiguation). Julian day is used in the Julian date (JD) system of… …   Wikipedia

  • Julian day — (JD)    a continuous count of days beginning with January 1, 4713 BC ( 4712 CE), which is start of what is called the Julian period. The French scholar Joseph Justus Scaliger (1540 1609) introduced the Julian period in 1582 (the same year the… …   Dictionary of units of measurement

  • Julian calendar — The Julian calendar began in 45 BC (709 AUC) as a reform of the Roman calendar by Julius Caesar. It was chosen after consultation with the astronomer Sosigenes of Alexandria and was probably designed to approximate the tropical year (known at… …   Wikipedia

  • Julián Carrillo — Trujillo (January 28, 1875 ndash;September 9, 1965) was a Mexican composer, conductor, violinist and music theorist, who discovered the Thirteenth Sound.BiographyCarrillo was born on January 28, 1875 in Ahualulco, a village in the state of San… …   Wikipedia

  • Ivan Julian — Infobox musical artist Name = Ivan Julian Img capt = Ivan Julian Img size = 250px Born = Birth date and age|1955|6|26|mf=y Instrument = Guitar, Bass guitar, Vocals, Genre = Punk rock Rock roll Occupation = Musician, singer, songwriter, producer… …   Wikipedia

  • Name day — A Swedish calendar page from 1712 with name days listed A name day is a tradition in many countries in Europe and Latin America that consists of celebrating the day of the year associated with one s given name. The custom originated with the… …   Wikipedia

  • MJD — Modified Julian Day (Governmental » US Government) **** Machado Joseph Disease (Medical » Physiology) * Mohenjodaro, Pakistan (Regional » Airport Codes) …   Abbreviations dictionary

  • Time standard — A time standard is any officially recognized specification for measuring time: either the rate at which time passes; or points in time; or both. For example, the standard for civil time specifies both time intervals and time of day. A time scale… …   Wikipedia

  • 1858 — Year 1858 (MDCCCLVIII) was a common year starting on Friday (link will display the full calendar) of the Gregorian Calendar (or a common year starting on Wednesday of the 12 day slower Julian calendar). Events of 1858January March * January 14… …   Wikipedia

  • November 17 — This article is about the date. For the Marxist group in Greece, see Revolutionary Organization 17 November. << November 2011 >> Su Mo Tu We Th Fr Sa …   Wikipedia

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”