Subject: 30.0.50; Calendar shows eclipse for quarter moon

From: Ulrich Mueller <[email-masked]>
Date: Sun, 12 Feb 2023 20:57:36 +0100

$ emacs -Q
M-x calendar RET
M

This will show the following phases of the moon:

Saturday, January 7, 2023: Full Moon 12:07am (CET) 
Sunday, January 15, 2023: Last Quarter Moon 3:17am (CET) **  Eclipse possible **
Saturday, January 21, 2023: New Moon 9:56pm (CET) 
Saturday, January 28, 2023: First Quarter Moon 4:20pm (CET) **  Eclipse **
Sunday, February 5, 2023: Full Moon 7:28pm (CET) 
Monday, February 13, 2023: Last Quarter Moon 5:07pm (CET) **  Eclipse possible **
[...]

Note that it shows eclipses for first and last quarter moon which is
astronomically impossible.

In GNU Emacs 30.0.50 (build 1, x86_64-pc-linux-gnu, X toolkit, cairo
 version 1.17.6) of 2023-02-09 built on localhost
Repository revision: 1518fc5d7c5bedbbe35053696c7ec06020c81b05
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12101005
System Description: Gentoo Linux

Configured using:
 'configure --prefix=/usr --build=x86_64-pc-linux-gnu
 --host=x86_64-pc-linux-gnu --mandir=/usr/share/man
 --infodir=/usr/share/info --datadir=/usr/share --sysconfdir=/etc
 --localstatedir=/var/lib --datarootdir=/usr/share
 --disable-silent-rules --docdir=/usr/share/doc/emacs-30.0.9999
 --htmldir=/usr/share/doc/emacs-30.0.9999/html --libdir=/usr/lib64
 --program-suffix=-emacs-30-vcs --includedir=/usr/include/emacs-30-vcs
 --infodir=/usr/share/info/emacs-30-vcs --localstatedir=/var
 --enable-locallisppath=/etc/emacs:/usr/share/emacs/site-lisp
 --without-compress-install --without-hesiod --without-pop
 --with-file-notification=inotify --with-pdumper --enable-acl
 --with-dbus --with-modules --with-gameuser=:gamestat --with-libgmp
 --with-gpm --without-native-compilation --without-json
 --without-kerberos --without-kerberos5 --with-lcms2 --with-xml2
 --without-mailutils --without-selinux --without-sqlite3 --with-gnutls
 --without-libsystemd --with-threads --without-tree-sitter
 --without-wide-int --with-sound=alsa --with-zlib --with-x
 --without-pgtk --without-ns --without-gconf --with-gsettings
 --without-toolkit-scroll-bars --with-xpm --with-xft --with-cairo
 --with-harfbuzz --with-libotf --with-m17n-flt --with-x-toolkit=lucid
 --with-xaw3d --with-gif --with-jpeg --with-png --with-rsvg --with-tiff
 --without-webp --with-imagemagick --with-dumping=pdumper
 'CFLAGS=-march=native -ggdb -O2 -pipe' 'LDFLAGS=-Wl,-O1
 -Wl,--as-needed''

Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM GSETTINGS HARFBUZZ
IMAGEMAGICK JPEG LCMS2 LIBOTF LIBXML2 M17N_FLT MODULES NOTIFY INOTIFY
PDUMPER PNG RSVG SECCOMP SOUND THREADS TIFF X11 XAW3D XDBE XIM XINPUT2
XPM LUCID ZLIB

Important settings:
  value of $LC_CTYPE: en_GB.UTF-8
  value of $LC_TIME: en_GB.UTF-8
  value of $LANG: POSIX
  locale-coding-system: utf-8-unix

Major mode: Special

Minor modes in effect:
  tooltip-mode: t
  global-eldoc-mode: t
  show-paren-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  buffer-read-only: t
  line-number-mode: t
  indent-tabs-mode: t
  transient-mark-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message mailcap yank-media puny dired
dired-loaddefs rfc822 mml mml-sec password-cache epa derived epg rfc6068
epg-config gnus-util text-property-search mm-decode mm-bodies mm-encode
mail-parse rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047
rfc2045 ietf-drums mm-util mail-prsvr mail-utils time-date subr-x
cl-loaddefs cl-lib cal-julian lunar solar cal-dst mule-util cal-move
cal-menu calendar cal-loaddefs rmc iso-transl tooltip cconv eldoc paren
electric uniquify ediff-hook vc-hooks lisp-float-type elisp-mode mwheel
term/x-win x-win term/common-win x-dnd tool-bar dnd fontset image
regexp-opt fringe tabulated-list replace newcomment text-mode lisp-mode
prog-mode register page tab-bar menu-bar rfn-eshadow isearch easymenu
timer select scroll-bar mouse jit-lock font-lock syntax font-core
term/tty-colors frame minibuffer nadvice seq simple cl-generic
indonesian philippine cham georgian utf-8-lang misc-lang vietnamese
tibetan thai tai-viet lao korean japanese eucjp-ms cp51932 hebrew greek
romanian slovak czech european ethiopic indian cyrillic chinese
composite emoji-zwj charscript charprop case-table epa-hook
jka-cmpr-hook help abbrev obarray oclosure cl-preloaded button loaddefs
theme-loaddefs faces cus-face macroexp files window text-properties
overlay sha1 md5 base64 format env code-pages mule custom widget keymap
hashtable-print-readable backquote threads dbusbind inotify lcms2
dynamic-setting system-font-setting font-render-setting cairo x-toolkit
xinput2 x multi-tty make-network-process emacs)

Memory information:
((conses 16 45225 9891)
 (symbols 48 5661 0)
 (strings 32 15659 2104)
 (string-bytes 1 452825)
 (vectors 16 10193)
 (vector-slots 8 157214 14550)
 (floats 8 507 444)
 (intervals 56 611 0)
 (buffers 976 14))