A Lilian date is the number of days since the beginning of the Gregorian calendar on October 15, 1582, regarded as Lilian date 1. It was invented by Bruce G. Ohms of IBM in 1986 and is named for Aloysius Lilius, who devised the Gregorian Calendar.[1] Lilian dates can be used to calculate the number of days between any two dates occurring since the beginning of the Gregorian calendar. It is currently used by date conversion routines that are part of IBM Language Environment (LE) software[2] and in IBM AIXCOBOL.[3]
The Lilian date is only a date format: it is not tied to any particular time standard. Another, better known, date notation that is used for similar purposes is the Julian date, which is tied to Universal time (or some other closely related time scale, such as International Atomic Time). The Julian date always begins at noon, Universal Time, and a decimal fraction may be used to represent the time of day. In contrast, Ohms did not make any mention of time zones or time of day in his paper.[1]
If the Lilian date was to be reckoned in Universal Time, and if the Lilian date is taken to begin at midnight, the Lilian date can be obtained from the Julian date by subtracting 2,299,159.5 from the Julian date, and ignoring the decimal fraction in the result.
References
^ abOhms, Bruce G (1986). "Computer processing of dates outside the twentieth century". IBM Systems Journal. IBM. 25 (2): 244–251. doi:10.1147/sj.252.0244.
^"CEEDATM—Convert seconds to character timestamp". z/OS Language Environment Programming Reference. IBM. 2021-03-22.
^COBOL for AIX Programming Guide Version 5.1(PDF) (First ed.). IBM. June 2015. CEEDATE—convert Lilian date to character format. SC27-5404-00.
lilian, date, number, days, since, beginning, gregorian, calendar, october, 1582, regarded, invented, bruce, ohms, 1986, named, aloysius, lilius, devised, gregorian, calendar, used, calculate, number, days, between, dates, occurring, since, beginning, gregoria. A Lilian date is the number of days since the beginning of the Gregorian calendar on October 15 1582 regarded as Lilian date 1 It was invented by Bruce G Ohms of IBM in 1986 and is named for Aloysius Lilius who devised the Gregorian Calendar 1 Lilian dates can be used to calculate the number of days between any two dates occurring since the beginning of the Gregorian calendar It is currently used by date conversion routines that are part of IBM Language Environment LE software 2 and in IBM AIX COBOL 3 The Lilian date is only a date format it is not tied to any particular time standard Another better known date notation that is used for similar purposes is the Julian date which is tied to Universal time or some other closely related time scale such as International Atomic Time The Julian date always begins at noon Universal Time and a decimal fraction may be used to represent the time of day In contrast Ohms did not make any mention of time zones or time of day in his paper 1 If the Lilian date was to be reckoned in Universal Time and if the Lilian date is taken to begin at midnight the Lilian date can be obtained from the Julian date by subtracting 2 299 159 5 from the Julian date and ignoring the decimal fraction in the result References Edit a b Ohms Bruce G 1986 Computer processing of dates outside the twentieth century IBM Systems Journal IBM 25 2 244 251 doi 10 1147 sj 252 0244 CEEDATM Convert seconds to character timestamp z OS Language Environment Programming Reference IBM 2021 03 22 COBOL for AIX Programming Guide Version 5 1 PDF First ed IBM June 2015 CEEDATE convert Lilian date to character format SC27 5404 00 See also EditRata Die This science article is a stub You can help Wikipedia by expanding it vte This technology related article is a stub You can help Wikipedia by expanding it vte Retrieved from https en wikipedia org w index php title Lilian date amp oldid 1161062749, wikipedia, wiki, book, books, library,
