-;;; lunar.el --- calendar functions for phases of the moon.
+;;; lunar.el --- calendar functions for phases of the moon
-;; Copyright (C) 1992 Free Software Foundation, Inc.
+;; Copyright (C) 1992, 1993, 1995, 1997, 2001, 2002, 2003, 2004, 2005,
+;; 2006 Free Software Foundation, Inc.
;; Author: Edward M. Reingold <reingold@cs.uiuc.edu>
-;; Keywords: moon, lunar phases, calendar, diary
+;; Maintainer: Glenn Morris <rgm@gnu.org>
+;; Keywords: calendar
+;; Human-Keywords: moon, lunar phases, calendar, diary
;; This file is part of GNU Emacs.
+;; GNU Emacs is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 2, or (at your option)
+;; any later version.
+
;; GNU Emacs is distributed in the hope that it will be useful,
-;; but WITHOUT ANY WARRANTY. No author or distributor
-;; accepts responsibility to anyone for the consequences of using it
-;; or for whether it serves any particular purpose or works at all,
-;; unless he says so in writing. Refer to the GNU Emacs General Public
-;; License for full details.
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;; GNU General Public License for more details.
-;; Everyone is granted permission to copy, modify and redistribute
-;; GNU Emacs, but only under the conditions described in the
-;; GNU Emacs General Public License. A copy of this license is
-;; supposed to have been given to you along with GNU Emacs so you
-;; can know your rights and responsibilities. It should be in a
-;; file named COPYING. Among other things, the copyright notice
-;; and this notice must be preserved on all copies.
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs; see the file COPYING. If not, write to the
+;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+;; Boston, MA 02110-1301, USA.
;;; Commentary:
;; diary.el.
;; Based on ``Astronomical Formulae for Calculators,'' 3rd ed., by Jean Meeus,
-;; Willmann-Bell, Inc., 1985.
+;; Willmann-Bell, Inc., 1985 and ``Astronomical Algorithms'' by Jean Meeus,
+;; Willmann-Bell, Inc., 1991.
;;
;; WARNING: The calculations will be accurate only to within a few minutes.
;; The author would be delighted to have an astronomically more sophisticated
;; person rewrite the code for the lunar calculations in this file!
+;; Technical details of all the calendrical calculations can be found in
+;; ``Calendrical Calculations: The Millennium Edition'' by Edward M. Reingold
+;; and Nachum Dershowitz, Cambridge University Press (2001).
+
;; Comments, corrections, and improvements should be sent to
;; Edward M. Reingold Department of Computer Science
;; (217) 333-6733 University of Illinois at Urbana-Champaign
;;; Code:
+(defvar date)
+(defvar displayed-month)
+(defvar displayed-year)
+
(if (fboundp 'atan)
(require 'lisp-float-type)
- (error "Lunar calculations impossible since floating point is unavailable."))
+ (error "Lunar calculations impossible since floating point is unavailable"))
(require 'solar)
(increment-calendar-month end-month end-year 3)
(increment-calendar-month start-month start-year -1)
(let* ((end-date (list (list end-month 1 end-year)))
- (start-date (list (list start-month
+ (start-date (list (list start-month
(calendar-last-day-of-month
start-month start-year)
start-year)))
Integer below INDEX/4 gives the lunation number, counting from Jan 1, 1900;
remainder mod 4 gives the phase: 0 new moon, 1 first quarter, 2 full moon,
3 last quarter."
- (let* ((phase (% index 4))
+ (let* ((phase (mod index 4))
(index (/ index 4.0))
(time (/ index 1236.85))
(date (+ (calendar-absolute-from-gregorian '(1 0.5 1900))
(solar-sin-degrees (+ 166.56
(* 132.87 time)
(* -0.009173 time time))))))
- (sun-anomaly (solar-mod
+ (sun-anomaly (mod
(+ 359.2242
(* 29.105356 index)
(* -0.0000333 time time)
(* -0.00000347 time time time))
360.0))
- (moon-anomaly (solar-mod
+ (moon-anomaly (mod
(+ 306.0253
(* 385.81691806 index)
(* 0.0107306 time time)
(* 0.00001236 time time time))
360.0))
- (moon-lat (solar-mod
+ (moon-lat (mod
(+ 21.2964
(* 390.67050646 index)
(* -0.0016528 time time)
((= phase 2) (- adjustment adj))
(t adjustment)))
(date (+ date adjustment))
- (calendar-standard-time-zone-name
- (if calendar-time-zone calendar-standard-time-zone-name "UT"))
- (calendar-daylight-savings-starts
- (if calendar-time-zone calendar-daylight-savings-starts))
- (calendar-daylight-savings-ends
- (if calendar-time-zone calendar-daylight-savings-ends))
- (calendar-time-zone (if calendar-time-zone calendar-time-zone 0))
- (year (extract-calendar-year
- (calendar-gregorian-from-absolute (truncate date))))
- (dst (and calendar-daylight-savings-starts
- calendar-daylight-savings-ends
- (<= (calendar-absolute-from-gregorian
- (eval calendar-daylight-savings-starts))
- date)
- (< date
- (calendar-absolute-from-gregorian
- (eval calendar-daylight-savings-ends)))))
- (date (+ date
- (/ (+ (if dst 60 0) calendar-time-zone) 60.0 24.0)
- (- (/ (solar-ephemeris-correction year) 60.0 24.0))))
+ (date (+ date (/ (- calendar-time-zone
+ (solar-ephemeris-correction
+ (extract-calendar-year
+ (calendar-gregorian-from-absolute
+ (truncate date)))))
+ 60.0 24.0)))
(time (* 24 (- date (truncate date))))
- (date (calendar-gregorian-from-absolute (truncate date)))
- (time-zone calendar-time-zone)
- (time-zone (if dst
- calendar-daylight-time-zone-name
- calendar-standard-time-zone-name))
- (24-hours (truncate time))
- (12-hours (format "%d" (if (> 24-hours 12)
- (- 24-hours 12)
- (if (= 24-hours 0) 12 24-hours))))
- (am-pm (if (>= 24-hours 12) "pm" "am"))
- (minutes (format "%02d" (round (* 60 (- time 24-hours)))))
- (24-hours (format "%02d" 24-hours))
- (time (mapconcat 'eval calendar-time-display-form "")))
- (list date time phase)))
+ (date (calendar-gregorian-from-absolute (truncate date)))
+ (adj (dst-adjust-time date time)))
+ (list (car adj) (apply 'solar-time-string (cdr adj)) phase)))
(defun lunar-phase-name (phase)
"Name of lunar PHASE.
(let ((m1 displayed-month)
(y1 displayed-year)
(m2 displayed-month)
- (y2 displayed-year)
- (lunar-phases-buffer "*Phases of Moon*"))
+ (y2 displayed-year))
(increment-calendar-month m1 y1 -1)
(increment-calendar-month m2 y2 1)
(set-buffer (get-buffer-create lunar-phases-buffer))
(setq buffer-read-only nil)
(calendar-set-mode-line
- (format "Phases of the moon from %s, %d to %s, %d%%-"
- (calendar-month-name m1) y1 (calendar-month-name m2) y2))
+ (if (= y1 y2)
+ (format "Phases of the Moon from %s to %s, %d%%-"
+ (calendar-month-name m1) (calendar-month-name m2) y2)
+ (format "Phases of the Moon from %s, %d to %s, %d%%-"
+ (calendar-month-name m1) y1 (calendar-month-name m2) y2)))
(erase-buffer)
(insert
(mapconcat
This function is suitable for execution in a .emacs file."
(interactive "P")
(save-excursion
- (let* ((completion-ignore-case t)
- (date (calendar-current-date))
- (displayed-month
- (if arg
- (cdr (assoc
- (capitalize
- (completing-read
- "Month name: "
- (mapcar 'list (append calendar-month-name-array nil))
- nil t))
- (calendar-make-alist calendar-month-name-array)))
- (extract-calendar-month date)))
- (displayed-year
- (if arg
- (calendar-read
- "Year (>0): "
- '(lambda (x) (> x 0))
- (int-to-string
- (extract-calendar-year (calendar-current-date))))
- (extract-calendar-year date))))
+ (let* ((date (if arg
+ (calendar-read-date t)
+ (calendar-current-date)))
+ (displayed-month (extract-calendar-month date))
+ (displayed-year (extract-calendar-year date)))
(calendar-phases-of-moon))))
-(defun diary-phases-of-moon ()
- "Moon phases diary entry."
+(defun diary-phases-of-moon (&optional mark)
+"Moon phases diary entry.
+
+An optional parameter MARK specifies a face or single-character string to
+use when highlighting the day in the calendar."
(let* ((index (* 4
(truncate
(* 12.3685
(setq index (1+ index))
(setq phase (lunar-phase index)))
(if (calendar-date-equal (car phase) date)
- (concat (lunar-phase-name (car (cdr (cdr phase)))) " "
- (car (cdr phase))))))
+ (cons mark (concat (lunar-phase-name (car (cdr (cdr phase)))) " "
+ (car (cdr phase)))))))
+
+
+;; For the Chinese calendar the calculations for the new moon need to be more
+;; accurate than those above, so we use more terms in the approximation.
+
+(defun lunar-new-moon-time (k)
+ "Astronomical (Julian) day number of K th new moon."
+ (let* ((T (/ k 1236.85))
+ (T2 (* T T))
+ (T3 (* T T T))
+ (T4 (* T2 T2))
+ (JDE (+ 2451550.09765
+ (* 29.530588853 k)
+ (* 0.0001337 T2)
+ (* -0.000000150 T3)
+ (* 0.00000000073 T4)))
+ (E (- 1 (* 0.002516 T) (* 0.0000074 T2)))
+ (sun-anomaly (+ 2.5534
+ (* 29.10535669 k)
+ (* -0.0000218 T2)
+ (* -0.00000011 T3)))
+ (moon-anomaly (+ 201.5643
+ (* 385.81693528 k)
+ (* 0.0107438 T2)
+ (* 0.00001239 T3)
+ (* -0.000000058 T4)))
+ (moon-argument (+ 160.7108
+ (* 390.67050274 k)
+ (* -0.0016341 T2)
+ (* -0.00000227 T3)
+ (* 0.000000011 T4)))
+ (omega (+ 124.7746
+ (* -1.56375580 k)
+ (* 0.0020691 T2)
+ (* 0.00000215 T3)))
+ (A1 (+ 299.77 (* 0.107408 k) (* -0.009173 T2)))
+ (A2 (+ 251.88 (* 0.016321 k)))
+ (A3 (+ 251.83 (* 26.641886 k)))
+ (A4 (+ 349.42 (* 36.412478 k)))
+ (A5 (+ 84.66 (* 18.206239 k)))
+ (A6 (+ 141.74 (* 53.303771 k)))
+ (A7 (+ 207.14 (* 2.453732 k)))
+ (A8 (+ 154.84 (* 7.306860 k)))
+ (A9 (+ 34.52 (* 27.261239 k)))
+ (A10 (+ 207.19 (* 0.121824 k)))
+ (A11 (+ 291.34 (* 1.844379 k)))
+ (A12 (+ 161.72 (* 24.198154 k)))
+ (A13 (+ 239.56 (* 25.513099 k)))
+ (A14 (+ 331.55 (* 3.592518 k)))
+ (correction
+ (+ (* -0.40720 (solar-sin-degrees moon-anomaly))
+ (* 0.17241 E (solar-sin-degrees sun-anomaly))
+ (* 0.01608 (solar-sin-degrees (* 2 moon-anomaly)))
+ (* 0.01039 (solar-sin-degrees (* 2 moon-argument)))
+ (* 0.00739 E (solar-sin-degrees (- moon-anomaly sun-anomaly)))
+ (* -0.00514 E (solar-sin-degrees (+ moon-anomaly sun-anomaly)))
+ (* 0.00208 E E (solar-sin-degrees (* 2 sun-anomaly)))
+ (* -0.00111 (solar-sin-degrees
+ (- moon-anomaly (* 2 moon-argument))))
+ (* -0.00057 (solar-sin-degrees
+ (+ moon-anomaly (* 2 moon-argument))))
+ (* 0.00056 E (solar-sin-degrees
+ (+ (* 2 moon-anomaly) sun-anomaly)))
+ (* -0.00042 (solar-sin-degrees (* 3 moon-anomaly)))
+ (* 0.00042 E (solar-sin-degrees
+ (+ sun-anomaly (* 2 moon-argument))))
+ (* 0.00038 E (solar-sin-degrees
+ (- sun-anomaly (* 2 moon-argument))))
+ (* -0.00024 E (solar-sin-degrees
+ (- (* 2 moon-anomaly) sun-anomaly)))
+ (* -0.00017 (solar-sin-degrees omega))
+ (* -0.00007 (solar-sin-degrees
+ (+ moon-anomaly (* 2 sun-anomaly))))
+ (* 0.00004 (solar-sin-degrees
+ (- (* 2 moon-anomaly) (* 2 moon-argument))))
+ (* 0.00004 (solar-sin-degrees (* 3 sun-anomaly)))
+ (* 0.00003 (solar-sin-degrees (+ moon-anomaly sun-anomaly
+ (* -2 moon-argument))))
+ (* 0.00003 (solar-sin-degrees
+ (+ (* 2 moon-anomaly) (* 2 moon-argument))))
+ (* -0.00003 (solar-sin-degrees (+ moon-anomaly sun-anomaly
+ (* 2 moon-argument))))
+ (* 0.00003 (solar-sin-degrees (- moon-anomaly sun-anomaly
+ (* -2 moon-argument))))
+ (* -0.00002 (solar-sin-degrees (- moon-anomaly sun-anomaly
+ (* 2 moon-argument))))
+ (* -0.00002 (solar-sin-degrees
+ (+ (* 3 moon-anomaly) sun-anomaly)))
+ (* 0.00002 (solar-sin-degrees (* 4 moon-anomaly)))))
+ (additional
+ (+ (* 0.000325 (solar-sin-degrees A1))
+ (* 0.000165 (solar-sin-degrees A2))
+ (* 0.000164 (solar-sin-degrees A3))
+ (* 0.000126 (solar-sin-degrees A4))
+ (* 0.000110 (solar-sin-degrees A5))
+ (* 0.000062 (solar-sin-degrees A6))
+ (* 0.000060 (solar-sin-degrees A7))
+ (* 0.000056 (solar-sin-degrees A8))
+ (* 0.000047 (solar-sin-degrees A9))
+ (* 0.000042 (solar-sin-degrees A10))
+ (* 0.000040 (solar-sin-degrees A11))
+ (* 0.000037 (solar-sin-degrees A12))
+ (* 0.000035 (solar-sin-degrees A13))
+ (* 0.000023 (solar-sin-degrees A14))))
+ (newJDE (+ JDE correction additional)))
+ (+ newJDE
+ (- (solar-ephemeris-correction
+ (extract-calendar-year
+ (calendar-gregorian-from-absolute
+ (floor (calendar-absolute-from-astro newJDE))))))
+ (/ calendar-time-zone 60.0 24.0))))
+
+(defun lunar-new-moon-on-or-after (d)
+ "Astronomical (Julian) day number of first new moon on or after astronomical
+\(Julian) day number d. The fractional part is the time of day.
+
+The date and time are local time, including any daylight savings rules,
+as governed by the values of calendar-daylight-savings-starts,
+calendar-daylight-savings-starts-time, calendar-daylight-savings-ends,
+calendar-daylight-savings-ends-time, calendar-daylight-time-offset, and
+calendar-time-zone."
+ (let* ((date (calendar-gregorian-from-absolute
+ (floor (calendar-absolute-from-astro d))))
+ (year (+ (extract-calendar-year date)
+ (/ (calendar-day-number date) 365.25)))
+ (k (floor (* (- year 2000.0) 12.3685)))
+ (date (lunar-new-moon-time k)))
+ (while (< date d)
+ (setq k (1+ k))
+ (setq date (lunar-new-moon-time k)))
+ (let* ((a-date (calendar-absolute-from-astro date))
+ (time (* 24 (- a-date (truncate a-date))))
+ (date (calendar-gregorian-from-absolute (truncate a-date)))
+ (adj (dst-adjust-time date time)))
+ (calendar-astro-from-absolute
+ (+ (calendar-absolute-from-gregorian (car adj))
+ (/ (car (cdr adj)) 24.0))))))
(provide 'lunar)
+;;; arch-tag: 72f0b8a4-7bcc-4a1b-b67a-ff53c4a1d222
;;; lunar.el ends here