references.bib

% References for proleptic_UTC and avoid_time_t

% Copyright © 2026 by John Sauter.
% Licensed under the Creative Commons Attribution-ShareAlike 4.0 International
% license.  See https://creativecommons.org/license/by-sa/4.0/.

%  Bibtex
@ARTICLE{2004JHA....35..327M,
   author = {{Morrison}, L.~V. and {Stephenson}, F.~R.},
    title = "{Historical values of the Earth's clock error {$\Delta$}T and the calculation of eclipses}",
  journal = {Journal for the History of Astronomy},
 keywords = {History of Astronomy},
     year = 2004,
    month = aug,
   volume = 35,
    pages = {327-336},
     doi = {10.1177/002182860403500305},
     note = {URL: \href{https://ui.adsabs.harvard.edu/abs/2004JHA....35..327M}{https://ui.adsabs.harvard.edu/abs/2004JHA....35..327M} {Provided by the SAO/NASA Astrophysics Data System}}
}

% Bibtex
@ARTICLE{JBS_001,
      author = {{Sauter}, John},
       title = "{Extending Coordinated Universal Time to Dates Before 1972}",
    keywords = {Coordinated Universal Time; UTC; proleptic UTC;
                Gregorian calendar; proleptic Gregorian calendar;
		leap seconds; delta T; $\Delta$T;
		proleptic UTC with leap seconds},
        year = 2026,
       month = feb,
         day = 13,
    abstract = {Using ancient observations of the Sun and Moon,
                construct a time scale using the modern definition
		of Coordinated Universal Time to cover the
                past \num{4000} years.
		Use that time scale to construct a table of leap seconds.},
        note = {URL: \href{https://www.systemeyescomputerstore.com/leap\_seconds/proleptic\_UTC.pdf}{https://www.systemeyescomputerstore.com/leap\_seconds/proleptic\_UTC.pdf}}
	}

% Bibtex
@ARTICLE{JBS_002,
      author = {{Sauter}, John},
       title = "{Avoid Using POSIX time_t for Telling Time}",
    keywords = {Coordinated Universal Time; UTC; POSIX; time\_t},
        year = 2026,
       month = feb,
         day = 13,
    abstract = {The POSIX data type time_t is defined in a way that
                leads to errors in application programs when it is
		used for telling time.  Here is how to avoid using
		it for that purpose.},
	note = {URL: \href{https://www.systemeyescomputerstore.com/leap\_seconds/avoid\_time\_t.pdf}{https://www.systemeyescomputerstore.com/leap\_seconds/avoid\_time\_t.pdf}}
	}

%  Bibtex
@ARTICLE{2005JHA....36..339M,
   author = {{Morrison}, L.~V. and {Stephenson}, F.~R.},
    title = "{Addendum: Historical values of the Earth's clock error}",
  journal = {Journal for the History of Astronomy},
 keywords = {History of Astronomy},
     year = 2005,
    month = aug,
   volume = 36,
    pages = {339},
     note = {URL: \href{https://ui.adsabs.harvard.edu/abs/2005JHA....36..339M}{https://ui.adsabs.harvard.edu/abs/2005JHA....36..339M} Provided by the SAO/NASA Astrophysics Data System}
}

%  Bibtex 
@ARTICLE{1997A&A...322..347S,
   author = {{Stephenson}, F.~R. and {Jones}, J.~E. and {Morrison}, L.~V.},
    title = "{The solar eclipse observed by Clavius in A.D. 1567.}",
  journal = {Astronomy and Astrophysics},
 keywords = {ECLIPSES, TIME, EARTH},
     year = 1997,
    month = jun,
   volume = 322,
    pages = {347-351},
     note = {URL: \href{https://ui.adsabs.harvard.edu/abs/1997A\%26A...322..347S}{https://ui.adsabs.harvard.edu/abs/1997A\%26A...322..347S} {Provided by the SAO/NASA Astrophysics Data System}}
}

@ARTICLE{2011ASSP...23....3S,
   author = {{Stephenson}, F.~R.},
    title = "{Historical Eclipses and Earth's Rotation: 700 BC--AD 1600}",
  journal = {Astrophysics and Space Science Proceedings},
 keywords = {Physics},
     year = 2011,
   volume = 23,
    pages = {3},
      doi = {10.1007/978-1-4419-8161-5_1},
     note = {URL: \href{https://ui.adsabs.harvard.edu/abs/2011ASSP...23....3S}{https://ui.adsabs.harvard.edu/abs/2011ASSP...23....3S} {Provided by the SAO/NASA Astrophysics Data System}},
 abstract = {For the whole of the pre-telescopic period, eclipse observations
 have proved to be by far the best data with which to determine changes in the
 Earth's rate of rotation.  These changes -- on the scale of
 milliseconds -- are produced by both the tides and a variety of non-tidal
 mechanisms.  Each individual observation leads to a result for ΔT (the
 cumulative effect of changes in the Earth's spin rate). Over a period of many
 centuries, this parameter can attain several hours and thus can be determined
 using fairly crude observations.
 
 Recently I have extended previous investigations by introducing hitherto
 unused observations and reinterpreting some of the more reliable existing
 data: especially in the periods from 700 BC to 50 BC and from AD 300 to 800.
 This has led to the derivation of revised ΔT values over much of the
 historical period.} 
}

@ARTICLE{1986PEPI...44..281M,
   author = {{McCarthy}, D.~D. and {Babcock}, A.~K.},
    title = "{The length of day since 1656}",
  journal = {Physics of the Earth and Planetary Interiors},
     year = 1986,
    month = nov,
   volume = 44,
    pages = {281-292},
      doi = {10.1016/0031-9201(86)90077-4},
      note = {URL: \href{https://ui.adsabs.harvard.edu/abs/1986PEPI...44..281M}{https://ui.adsabs.harvard.edu/abs/1986PEPI...44..281M}},
 abstract = {Observed values of the difference between the time determined
 using the rotation of the Earth and a uniform time scale are available since
 1627, with useful observations becoming available in 1656.
 These early data were recorded with low precision and must be smoothed
 numerically in order to be useful for the derivation of estimates of the
 difference between the actual length of the day and the standard 24 h,
 known as excess length of day, or the Earth's rotational speed.
 Modern data requires no smoothing. The observational data have been adjusted
 to be consistent with one estimate of the lunar acceleration and smoothed
 so that the internal and external precision of the observations are
 approximately equal. The final values along with the derived excess length of
 day are presented and their spectra are discussed.
 This paper was presented at the AGU Spring Meeting 1984 and may be
 read in conjunction with other papers from the symposium
 ‘The Irregularities in the Secular Variation and Geodynamic
 Implications’ published in this journal as a special issue
 (Volume 39 No. 4).  Provided by the SAO/NASA Astrophysics Data System}
}

@ARTICLE{Mccarthy01081993,
   author = {{Mccarthy}, Dennis D. and {Luzum}, Brian J.}, 
    title = "{An Analysis of Tidal Variations in the Length of Day}",
   volume = {114}, 
   number = {2}, 
    pages = {341-346}, 
     year = {1993}, 
      doi = {10.1111/j.1365-246X.1993.tb03922.x}, 
 abstract = {Observations of the length of day, corrected for the effects of
 variations in the angular momentum due to changes in wind velocity and
 atmospheric pressure, ocean-tide heights and currents, and solid-Earth zonal
 tides, were analysed. The (1992) IERS Standards model for the effects of
 zonal tides on the Earth's rotation, which includes ocean-tidal effects,
 adequately accounts for the observations of the high-frequency
 (periods between one and 30 days) variations in the length of day at the
 present level of accuracy. A currently unexplained semi-annual variation
 in the length of day remains, but this may be due to the unmodelled effects
 of stratospheric winds. The power spectrum of the remaining variations with
 periods less than 20 days is essentially that of a white-noise process.
 The amplitudes of the remaining unexplained variations in length of day are
 less than 30 microseconds.}, 
     note = {URL: \href{https://gji.oxfordjournals.org/content/114/2/341.abstract}{https://gji.oxfordjournals.org/content/114/2/341.abstract}},
   eprint = {https://gji.oxfordjournals.org/content/114/2/341.full.pdf+html}, 
  journal = {Geophysical Journal International} 
}

@article{Jordi01061994,
   author = {{Jordi}, C. and {Morrison}, L.~V. and {Rosen}, R.~D. and {Salstein}, D.~A. and {Rosselló}, G.}, 
    title = "{Fluctuations in the Earth's rotation since 1830 from high-resolution astronomical data}",
   volume = {117}, 
   number = {3}, 
    pages = {811-818}, 
     year = {1994}, 
      doi = {10.1111/j.1365-246X.1994.tb02471.x}, 
 abstract = {Fluctuations in the Earth's rotation since 1830, as evidenced by
             changes in the length of the day, are derived from astronomical
	     data having subannual resolution. Before 1955.5, timings of lunar
	     occultations are used; after 1955.5, the data are taken from the
	     time series TAI-UT1. Although the data in the earliest period,
	     1830–90, display decade fluctuations in the length of the day,
	     they are not accurate enough to reveal interannual variations.
	     In this regard, also, the results from 1890–1925 are somewhat
	     dubious. The quality of the data after 1925, though, is such
	     that the temporal behaviour of the interannual fluctuations in
	     the length of the day can be traced with confidence. We present
	     plots of the interannual fluctuations in the period 1890–1987
	     and the longer-term decade fluctuations in the period 1830–1983.
	     The interannual fluctuations in the length of the day since 1925
	     are compared with an index of the El Niño/Southern Oscillation
	     (ENSO) phenomenon in the ocean-atmosphere system and are
	     subjected to spectral analysis. The results support the
	     conclusions reached by other authors that these fluctuations are
	     linked to circulation changes in the atmosphere associated with
	     ENSO, and in part to the quasi-biennial oscillation in the
	     equatorial stratosphere's zonal winds. A spectral analysis of our
	     62 yr series of length of day values since 1925 reveals two
	     significant peaks in the interannual range 2–4 yr.
	     One is roughly biennial and the other is about twice this period,
	     broadly supporting results obtained previously from shorter
	     records.  Our analysis of high-resolution data, therefore,
	     contributes to ongoing efforts to establish a close relationship
	     between the length of the day and aspects of the global climate
	     system in the period before modern data became available in
	     1955.5.}, 
     note = {URL: \href{https://gji.oxfordjournals.org/content/117/3/811.abstract}{https://gji.oxfordjournals.org/content/117/3/811.abstract}},
   eprint = {https://gji.oxfordjournals.org/content/117/3/811.full.pdf+html}, 
  journal = {Geophysical Journal International},
 keywords = {atmospheric circulation, earth rotation, lunar occultations,
             time-scales}
}

@ARTICLE{10555529,
  author={IEEE},
  journal="{IEEE/Open Group Std 1003.1-2024
  (Revision of IEEE Std 1003.1-2017)}", 
  title="{IEEE/Open Group Standard for Information Technology--Portable
  Operating System Interface (POSIX™) Base Specifications, Issue 8}", 
  year={2024},
  volume={},
  number={},
  pages={1-4107},
  keywords={IEEE Standards;Information technology;Open
                  systems;Operating systems;Application programming
                  interfaces;application program interface
                  (API);argument;asynchronous;basic regular expression
                  (BRE);built-in utility;byte;child;command language
                  interpreter;CPU;extended regular expression
                  (ERE);FIFO;file access control mechanism;IEEE
                  1003.1™;input/output (I/O);job
                  control;network;parent;portable operating system
                  interface
                  (POSIX™);shell;stream;string;synchronous;system;thread;X/Open
                  System Interface (XSI)},
  abstract={POSIX.1-2024 is simultaneously IEEE Std 1003.1™-2024 and
                  The Open Group Standard Base Specifications, Issue
                  8. POSIX.1-2024 defines a standard operating system
                  interface and environment, including a command
                  interpreter (or “shell”), and common utility
                  programs to support applications portability at the
                  source code level. POSIX.1-2024 is intended to be
                  used by both application developers and system
                  implementors and comprises four major components
                  (each in an associated volume): --General terms,
                  concepts, and interfaces common to all volumes of
                  this standard, including utility conventions and
                  C-language header definitions, are included in the
                  Base Definitions volume. --Definitions for system
                  service functions and subroutines, language-specific
                  system services for the C programming language,
                  function issues, including portability, error
                  handling, and error recovery, are included in the
                  System Interfaces volume. --Definitions for a
                  standard source code-level interface to command
                  interpretation services (a “shell”) and common
                  utility programs for application programs are
                  included in the Shell and Utilities
                  volume. --Extended rationale that did not fit well
                  into the rest of the document structure, which
                  contains historical information concerning the
                  contents of POSIX.1-2024 and why features were
                  included or discarded by the standard developers, is
                  included in the Rationale (Informative) volume.},
  doi={10.1109/IEEESTD.2024.10555529},
  }

@ARTICLE{7582338,
  author = {IEEE},
  journal = {IEEE Std 1003.1, 2016 Edition (incorporates IEEE Std 1003.1-2008, IEEE Std 1003.1-2008/Cor 1-2013, and IEEE Std 1003.1-2008/Cor 2-2016)},
  title = "{Standard for Information Technology--Portable Operating System Interface (POSIX{\textregistered}) Base Specifications, Issue 7}",
  year = {2016},
  volume={},
  number={},
  pages = {1-3957},
  abstract = {POSIX.1-2008 is simultaneously IEEE Std Specifications, Issue 7.
   This 2016 Edition includes 1003.1-2008/Cor 2-2016 incorporated into
   IEEE Corrigenda address problems discovered since the approval of
   IEEE Std 1003.1-2008. POSIX.1-2008 defines a standard operating system
   interface and environment, including a command interpreter (or “shell”),
   and common utility programs to support applications portability
   at the source code level. POSIX.1-2008 is intended to be used by both
   application developers and system implementors and comprises four
   major components (each in an associated volume): General terms,
   concepts, and interfaces common to all volumes of this standard,
   including utility conventions and C-language header definitions,
   are included in the Base Definitions volume.
   Definitions for system service functions and subroutines,
   language-specific system services for the C programming language,
   function issues, including portability, error handling, and
   error recovery, are included in the System Interfaces volume.
   Definitions for a standard source code-level interface to command
   interpretation services (a “shell”) and common utility programs
   for application programs are included in the Shell and Utilities volume.
   Extended rationale that did not fit well into the rest of the document
   structure, which contains historical information concerning the
   contents of POSIX.1-2008 and why features were included or discarded
   by the standard developers, is included in the
   Rationale (Informative) volume.},
  keywords = {C language;IEEE standards;error handling;expert system shells;
   operating systems (computers);program interpreters;programming languages;
   software portability;source code (software);subroutines;system recovery;
   utility programs;1003.1-2008/Cor 2-2016;C programming languages;
   C-language header definitions;IEEE Std 1003.1-2008;
   IEEE corrigenda address problems;
   IEEE std specifications, issue 7;POSIX.1-2008;application developers;
   application programs;applications portability support;
   base definitions volume;command interpretation services;
   command interpreter;common utility programs;error handling;
   error recovery;function issues;information technology standard;
   language-specific system services;portable operating system interface;
   rationale volume;shell and utilities volume;
   source code level;standard operating system interface;
   standard source code-level interface;subroutines;system implementors;
   system interfaces volume;system service functions;utility conventions;
   Access control;Application programming interfaces;Batch jobs;
   File access management;IEEE Standards;Media streaming;
   Open system interfaces;CPU;FIFO;IEEE 1003.1(TM);
   X/Open System Interface (XSI);application program interface (API);
   argument;asynchronous;basic regular expression (BRE);batch job;
   batch system;built-in utility;byte;child;command language interpreter;
   extended regular expression (ERE);file access control mechanism;
   input/output (I/O);job control;network;parent;
   portable operating system interface (POSIX(R));shell;stream;string;
   synchronous;system;thread},
  doi = {10.1109/IEEESTD.2016.7582338},
  ISSN={},
  month = {Sep.},
}

@article {Stephenson20160404,
	author = {Stephenson, F. R. and Morrison, L. V. and
	Hohenkerk, C. Y. },
	title = "{Measurement of the Earth{\textquoteright}s rotation:
	720 BC to AD 2015}",
	volume = {472},
	number = {2196},
	year = {2016},
	doi = {10.1098/rspa.2016.0404},
	publisher = {The Royal Society},
	abstract = {New compilations of records of ancient and medieval
	eclipses in the period 720 BC to AD 1600, and of lunar occultations
	of stars in AD 1600{\textendash}2015, are analysed to investigate
	variations in the Earth{\textquoteright}s rate of rotation.
	It is found that the rate of rotation departs from uniformity,
	such that the change in the length of the mean solar day (lod)
	increases at an average rate of $+1.8$ ms per century.
	This is significantly less than the rate predicted on the basis of
	tidal friction, which is $+2.3$ ms per century.
	Besides this linear change in the lod, there are fluctuations
	about this trend on time scales of decades to centuries.
	A power spectral density analysis of fluctuations in the
	range 2{\textendash}30 years follows a power law with exponent $-1.3$,
	and there is evidence of increased power at a period of 6 years.
	There is some indication of an oscillation in the lod with a period
	of roughly 1500 years.
	Our measurements of the Earth{\textquoteright}s rotation for the
	period 720 BC to AD 2015 set firm boundaries for future work on
	post-glacial rebound and core{\textendash}mantle coupling
	which are invoked to explain the departures from tidal friction.},
	issn = {1471-2946},
	note = {URL: \href{https://rspa.royalsocietypublishing.org/content/472/2196/20160404}{https://rspa.royalsocietypublishing.org/content/472/2196/20160404}},
	eprint = {https://rspa.royalsocietypublishing.org/content/472/2196/20160404.full.pdf},
	journal = {Proceedings of the Royal Society A:
	Mathematical, Physical and Engineering Sciences},
}

@article {Stephenson20210217,
	author = {Morrison, L. V. and Stephenson, F. R. and Hohenkerk, C. Y. and
	Zawilski, M. },
	title = "{Addendum 2020 to {\textquoteleft}Measurement of the 
        Earth{\textquoteright}s rotation: 720 BC to AD
	2015{\textquoteright}}",
	volume = {477},
	number = {2246},
	year = {2021},
	month={Feb},
	doi = {10.1098/rspa.2020.0776},
	publisher = {The Royal Society},
	abstract = {Historical reports of solar eclipses are added to our
	previous dataset (Stephenson et al. 2016 Proc. R. Soc. A 472 ,
	20160404 ( doi:10.1098/rspa.2016.0404 )) in order to refine our
	determination of centennial and longer-term changes since 720 BC in
	the rate of rotation of the Earth. The revised observed deceleration
	is −4.59 ± 0.08 × 10 ⁻²² rad s ⁻² . By comparison the predicted tidal
	deceleration based on the conservation of angular momentum in the
	Sun–Earth–Moon system is −6.39 ± 0.03 × 10 ⁻²² rad s ⁻² . These
	signify a mean accelerative component of +1.8 ± 0.1 × 10 ⁻²²
	rad s ⁻² . There is also evidence of an oscillatory variation in the
	rate with a period of about 14 centuries.},
	issn = {1364-5021},
	note = {URL: \href{https://royalsocietypublishing.org/doi/10.1098/rspa.2020.0776}{https://royalsocietypublishing.org/doi/10.1098/rspa.2020.0776}},
	eprint = {https://royalsocietypublishing.org/doi/pdf/10.1098/rspa.2020.0776},
	journal = {Proceedings of the Royal Society A:
	Mathematical, Physical and Engineering Sciences}
}