Rename README -> readme.org and add installation info.
Update copyright.
moon_position/elp_mpp02_lbr(): make precession optional.
visibility/planet_visibility_tonight(): reuse Sun riset data if possible.
visibility: use riset(for_night=.true.) to determine rise and set times.
riset: use new elemental version of deq().
riset/riset(_ipol/_ad)(): add for_night to compute times for night iso day.
riset: use more explicit floor() instead of int().
riset/riset(_ipol)(): correct for negative time ONLY for the Moon.
visibility: update comments.
riset/riset(_ipol()): improve comments.
riset/riset(_ipol)(): BUGFIX: do not correct for negative times for planets.
modules: reinstate plcon, used elsewhere.
Fix missing Doxygen comments.
src/modules: comment the rest of the module members.
Adding missing Doxygen comments.
date_time: SUFR_date_and_time/correct_time() -> consistent_date_time().
coordinates, riset: tidy up.
date_time: add subroutine ut2lt_ymdhms() to convert UT to LT.
riset/riset(_ipol()): add atmospheric refraction to transit altitude.
date_time: BUGIX: use hms_sss() iso hms(), second_fr.
riset: BUGFIX: use topocentric coordinates, not geocentric!
date_time/gettz(): swap variable names ltz0,ldsttp <=> tz0,dsttp.
date_time/gettz(): warn if dsttp is not set.
date_time: use new interface of libSUFR/system_clock_2_ymdhms().
date_time/set_date_and_time_to_system_clock(): use libSUFR; add option ut.
date_time: move system_clock_2_ymdhms() to libSUFR.
CMake/CompilerFlags_Fortran.cmake: trap overflow,underflow,denormal.
comets: BUGFIX: add format descriptors for all variables.
data, modules: rename variable TheSkydir -> TheSkyDatadir.
Updating licence.
Replace http: protocol -> https: for most urls.
Change licence.
visibility: make sky-brightness functions elemental.
data: fix two Doxygen issues.
planets/planet_position(): add keyword assume_jde.
planets/planet_position(): print JD and DeltaT in verbose mode.
planets/planet_magnitude(): stick in AA 1992 as Model 3.
planets/planet_magnitude(): use square brackets for arrays.
planets: merge planet_magnitude_new() into planet_magnitude().
planets/planet_magnitude(): several improvements in coding style.
planets/planet_position(): add dummy parameter magmdl; new Saturn magnitude.
planets/planet_position(): add dummy parameters aber and to_fk5.
planets,vsop: use 0.d0 iso VSOPtruncs() for full VSOP87 accuracy.
planets: planet_position(): return TRUE geocentric distance, not apparent.
sun: compute Sun magnitude more efficiently.
planets: minor updates.
planets/planet_position(): add choice for no nutation.
planets: do NOT compensate for light time for the Sun.
planets/planet_position(): BUGFIX: return TRUE distance for Sun!
date_time: add function calc_deltat_approx() for a cheap DeltaT.
planets/planet_position(): avoid division by zero; add verbose output.
nutation/nutation2000(): optionally return eps0.
nutation/nutation(): rename variable tt -> tjc for clarity.
planets/planet_position(): add optional dummy variable nutat.
date_time: print_date_time_and_location(): allow negative seconds.
planets/planet_position(): adding verbosity argument.
visibility: rename sky-brightness functions.
visibility: add functions to convert sky brightness.
visibility/limmag_full(): add verbosity and comments.
coordinates: fix typo.
comets: improve some comments.
comets/cometxyz(): provide more-informative divergence warnings.
comets: (re)name constants and (few-character) variables.
comets/cometxyz(): tidy up some unneded doubles.
comets/cometxyz(): conclude divergence if NaNs are produced.
coordinates: rename t11 -> t12 for t1**2.
coordinates,date_time: minor updates in spacing.
moon_position: fix typos in comments.
Update copyright.
Update copyright.
src/coordinates: update a few comments.
moon_position, nutation, sun: update references.
date_time: jd2dtm(),jd2dthm(): BUGFIX: check AFTER jd2cal() call.
daylight: BUGFIX: diffuse_radiation_Perez87(): return THREE components.
codemeta.json: fix licence entry.
Add CITATION.cff, codemeta.json.
date_time: jd2dtm(), jd2dthm(): check month number.
coordinates: use atmospheric_refraction_apparent().
coordinates: atmospheric_refraction_apparent(): make parameters optional.
coordinates: add function atmospheric_refraction_apparent().
coordinates/refract(): keep constant value for alt<-1.102°.
build/src/coordinates/aref(): return 0 for z0>90.
build/src/coordinates, src/riset: Update some comments, rephrase code.
date_time: add subroutine passover_gauss() to compute the Passover date.
date_time: add subroutine passover_gauss() to compute the Passover date.
Add subroutine easter_gauss() to compute the Easter date using Gauss' method.
Copy LICENSE to root.
coordinates/refract(): keep refraction constant when object is further below the horizon.
coordinates: add refract_sp() as a single-precision wrapper for refract().
Add a few references.