Commit | Line | Data |
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3afbc435 | 1 | ;;; lunar.el --- calendar functions for phases of the moon |
7e1dae73 | 2 | |
73b0cd50 | 3 | ;; Copyright (C) 1992-1993, 1995, 1997, 2001-2011 Free Software Foundation, Inc. |
7e1dae73 JB |
4 | |
5 | ;; Author: Edward M. Reingold <reingold@cs.uiuc.edu> | |
dbfca9c4 | 6 | ;; Maintainer: Glenn Morris <rgm@gnu.org> |
e9571d2a ER |
7 | ;; Keywords: calendar |
8 | ;; Human-Keywords: moon, lunar phases, calendar, diary | |
bd78fa1d | 9 | ;; Package: calendar |
7e1dae73 JB |
10 | |
11 | ;; This file is part of GNU Emacs. | |
12 | ||
2ed66575 | 13 | ;; GNU Emacs is free software: you can redistribute it and/or modify |
59243403 | 14 | ;; it under the terms of the GNU General Public License as published by |
2ed66575 GM |
15 | ;; the Free Software Foundation, either version 3 of the License, or |
16 | ;; (at your option) any later version. | |
59243403 | 17 | |
7e1dae73 | 18 | ;; GNU Emacs is distributed in the hope that it will be useful, |
59243403 RS |
19 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of |
20 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
21 | ;; GNU General Public License for more details. | |
22 | ||
23 | ;; You should have received a copy of the GNU General Public License | |
2ed66575 | 24 | ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. |
7e1dae73 JB |
25 | |
26 | ;;; Commentary: | |
27 | ||
4bd7ad5f | 28 | ;; See calendar.el. |
7e1dae73 JB |
29 | |
30 | ;; Based on ``Astronomical Formulae for Calculators,'' 3rd ed., by Jean Meeus, | |
8a45b040 ER |
31 | ;; Willmann-Bell, Inc., 1985 and ``Astronomical Algorithms'' by Jean Meeus, |
32 | ;; Willmann-Bell, Inc., 1991. | |
7e1dae73 JB |
33 | ;; |
34 | ;; WARNING: The calculations will be accurate only to within a few minutes. | |
35 | ||
36 | ;; The author would be delighted to have an astronomically more sophisticated | |
37 | ;; person rewrite the code for the lunar calculations in this file! | |
38 | ||
7e1dae73 JB |
39 | ;;; Code: |
40 | ||
164e17e1 | 41 | (require 'calendar) |
7e1dae73 | 42 | (require 'solar) |
164e17e1 | 43 | (require 'cal-dst) |
5c645a20 | 44 | ;; calendar-astro-to-absolute and v versa are cal-autoloads. |
164e17e1 | 45 | ;;;(require 'cal-julian) |
7e1dae73 | 46 | |
b4deec2e GM |
47 | (defcustom lunar-phase-names |
48 | '("New Moon" "First Quarter Moon" "Full Moon" "Last Quarter Moon") | |
49 | "List of names for the lunar phases." | |
50 | :type '(list | |
51 | (string :tag "New Moon") | |
52 | (string :tag "First Quarter Moon") | |
53 | (string :tag "Full Moon") | |
54 | (string :tag "Last Quarter Moon")) | |
55 | :group 'calendar | |
56 | :version "23.2") | |
57 | ||
7e1dae73 JB |
58 | (defun lunar-phase (index) |
59 | "Local date and time of lunar phase INDEX. | |
60 | Integer below INDEX/4 gives the lunation number, counting from Jan 1, 1900; | |
61 | remainder mod 4 gives the phase: 0 new moon, 1 first quarter, 2 full moon, | |
b4deec2e | 62 | 3 last quarter. Returns a list (DATE TIME PHASE)." |
b6c0aabf | 63 | (let* ((phase (mod index 4)) |
7e1dae73 JB |
64 | (index (/ index 4.0)) |
65 | (time (/ index 1236.85)) | |
66 | (date (+ (calendar-absolute-from-gregorian '(1 0.5 1900)) | |
67 | 0.75933 | |
b4deec2e | 68 | (* 29.53058868 index) ; FIXME 29.530588853? |
7e1dae73 JB |
69 | (* 0.0001178 time time) |
70 | (* -0.000000155 time time time) | |
71 | (* 0.00033 | |
72 | (solar-sin-degrees (+ 166.56 | |
73 | (* 132.87 time) | |
74 | (* -0.009173 time time)))))) | |
e7bb3aeb | 75 | (sun-anomaly (mod |
7e1dae73 JB |
76 | (+ 359.2242 |
77 | (* 29.105356 index) | |
78 | (* -0.0000333 time time) | |
79 | (* -0.00000347 time time time)) | |
80 | 360.0)) | |
e7bb3aeb | 81 | (moon-anomaly (mod |
7e1dae73 JB |
82 | (+ 306.0253 |
83 | (* 385.81691806 index) | |
84 | (* 0.0107306 time time) | |
85 | (* 0.00001236 time time time)) | |
86 | 360.0)) | |
e7bb3aeb | 87 | (moon-lat (mod |
7e1dae73 JB |
88 | (+ 21.2964 |
89 | (* 390.67050646 index) | |
90 | (* -0.0016528 time time) | |
91 | (* -0.00000239 time time time)) | |
92 | 360.0)) | |
93 | (adjustment | |
94 | (if (memq phase '(0 2)) | |
95 | (+ (* (- 0.1734 (* 0.000393 time)) | |
96 | (solar-sin-degrees sun-anomaly)) | |
97 | (* 0.0021 (solar-sin-degrees (* 2 sun-anomaly))) | |
98 | (* -0.4068 (solar-sin-degrees moon-anomaly)) | |
99 | (* 0.0161 (solar-sin-degrees (* 2 moon-anomaly))) | |
100 | (* -0.0004 (solar-sin-degrees (* 3 moon-anomaly))) | |
101 | (* 0.0104 (solar-sin-degrees (* 2 moon-lat))) | |
102 | (* -0.0051 (solar-sin-degrees (+ sun-anomaly moon-anomaly))) | |
103 | (* -0.0074 (solar-sin-degrees (- sun-anomaly moon-anomaly))) | |
104 | (* 0.0004 (solar-sin-degrees (+ (* 2 moon-lat) sun-anomaly))) | |
105 | (* -0.0004 (solar-sin-degrees (- (* 2 moon-lat) sun-anomaly))) | |
106 | (* -0.0006 (solar-sin-degrees | |
107 | (+ (* 2 moon-lat) moon-anomaly))) | |
108 | (* 0.0010 (solar-sin-degrees (- (* 2 moon-lat) moon-anomaly))) | |
109 | (* 0.0005 (solar-sin-degrees | |
110 | (+ (* 2 moon-anomaly) sun-anomaly)))) | |
111 | (+ (* (- 0.1721 (* 0.0004 time)) | |
112 | (solar-sin-degrees sun-anomaly)) | |
113 | (* 0.0021 (solar-sin-degrees (* 2 sun-anomaly))) | |
114 | (* -0.6280 (solar-sin-degrees moon-anomaly)) | |
115 | (* 0.0089 (solar-sin-degrees (* 2 moon-anomaly))) | |
116 | (* -0.0004 (solar-sin-degrees (* 3 moon-anomaly))) | |
117 | (* 0.0079 (solar-sin-degrees (* 2 moon-lat))) | |
118 | (* -0.0119 (solar-sin-degrees (+ sun-anomaly moon-anomaly))) | |
119 | (* -0.0047 (solar-sin-degrees (- sun-anomaly moon-anomaly))) | |
120 | (* 0.0003 (solar-sin-degrees (+ (* 2 moon-lat) sun-anomaly))) | |
121 | (* -0.0004 (solar-sin-degrees (- (* 2 moon-lat) sun-anomaly))) | |
122 | (* -0.0006 (solar-sin-degrees (+ (* 2 moon-lat) moon-anomaly))) | |
123 | (* 0.0021 (solar-sin-degrees (- (* 2 moon-lat) moon-anomaly))) | |
124 | (* 0.0003 (solar-sin-degrees | |
125 | (+ (* 2 moon-anomaly) sun-anomaly))) | |
126 | (* 0.0004 (solar-sin-degrees | |
127 | (- sun-anomaly (* 2 moon-anomaly)))) | |
128 | (* -0.0003 (solar-sin-degrees | |
9c0b9187 | 129 | (+ (* 2 sun-anomaly) moon-anomaly)))))) |
7e1dae73 JB |
130 | (adj (+ 0.0028 |
131 | (* -0.0004 (solar-cosine-degrees | |
132 | sun-anomaly)) | |
133 | (* 0.0003 (solar-cosine-degrees | |
134 | moon-anomaly)))) | |
135 | (adjustment (cond ((= phase 1) (+ adjustment adj)) | |
136 | ((= phase 2) (- adjustment adj)) | |
137 | (t adjustment))) | |
138 | (date (+ date adjustment)) | |
71ea27ee GM |
139 | (date (+ date (/ (- calendar-time-zone |
140 | (solar-ephemeris-correction | |
e803eab7 | 141 | (calendar-extract-year |
80e48f9f | 142 | (calendar-gregorian-from-absolute |
238c5cc1 | 143 | (truncate date))))) |
71ea27ee | 144 | 60.0 24.0))) |
7e1dae73 | 145 | (time (* 24 (- date (truncate date)))) |
71ea27ee | 146 | (date (calendar-gregorian-from-absolute (truncate date))) |
8a45b040 | 147 | (adj (dst-adjust-time date time))) |
e483c805 | 148 | (list (car adj) (apply 'solar-time-string (cdr adj)) phase))) |
7e1dae73 | 149 | |
b4deec2e GM |
150 | (defconst lunar-cycles-per-year 12.3685 ; 365.25/29.530588853 |
151 | "Mean number of lunar cycles per 365.25 day year.") | |
152 | ||
153 | ;; FIXME new-moon index; use in lunar-phase-list implies always below. | |
154 | (defun lunar-index (date) | |
155 | "Return the lunar index for Gregorian date DATE. | |
156 | This is 4 times the approximate number of new moons since 1 Jan 1900. | |
157 | The factor of 4 allows (mod INDEX 4) to represent the four quarters." | |
158 | (* 4 (truncate | |
159 | (* lunar-cycles-per-year | |
160 | ;; Years since 1900, as a real. | |
161 | (+ (calendar-extract-year date) | |
162 | (/ (calendar-day-number date) 366.0) | |
163 | -1900))))) | |
164 | ||
9c0b9187 GM |
165 | (defun lunar-phase-list (month year) |
166 | "List of lunar phases for three months starting with Gregorian MONTH, YEAR." | |
b4deec2e GM |
167 | (let* ((index (lunar-index (list month 1 year))) |
168 | (new-moon (lunar-phase index)) | |
169 | (end-date (let ((end-month month) | |
170 | (end-year year)) | |
e803eab7 | 171 | (calendar-increment-month end-month end-year 3) |
4bd7ad5f | 172 | (list (list end-month 1 end-year)))) |
b4deec2e GM |
173 | ;; Alternative for start-date: |
174 | ;;; (calendar-gregorian-from-absolute | |
175 | ;;; (1- (calendar-absolute-from-gregorian (list month 1 year)))) | |
4bd7ad5f | 176 | (start-date (progn |
b4deec2e GM |
177 | (calendar-increment-month month year -1) |
178 | (list (list month | |
179 | (calendar-last-day-of-month month year) | |
180 | year)))) | |
4bd7ad5f GM |
181 | list) |
182 | (while (calendar-date-compare new-moon end-date) | |
183 | (if (calendar-date-compare start-date new-moon) | |
184 | (setq list (append list (list new-moon)))) | |
185 | (setq index (1+ index) | |
186 | new-moon (lunar-phase index))) | |
187 | list)) | |
9c0b9187 | 188 | |
7e1dae73 JB |
189 | (defun lunar-phase-name (phase) |
190 | "Name of lunar PHASE. | |
191 | 0 = new moon, 1 = first quarter, 2 = full moon, 3 = last quarter." | |
b4deec2e | 192 | (nth phase lunar-phase-names)) |
7e1dae73 | 193 | |
e803eab7 | 194 | (defvar displayed-month) ; from calendar-generate |
9c0b9187 GM |
195 | (defvar displayed-year) |
196 | ||
fb97eeac | 197 | ;;;###cal-autoload |
dc67263c GM |
198 | (defun calendar-lunar-phases (&optional event) |
199 | "Create a buffer with the lunar phases for the current calendar window. | |
200 | If EVENT is non-nil, it's an event indicating the buffer position to | |
201 | use instead of point." | |
202 | (interactive (list last-nonmenu-event)) | |
203 | ;; If called from a menu, with the calendar window not selected. | |
204 | (with-current-buffer | |
205 | (if event (window-buffer (posn-window (event-start event))) | |
206 | (current-buffer)) | |
207 | (message "Computing phases of the moon...") | |
208 | (let ((m1 displayed-month) | |
209 | (y1 displayed-year) | |
210 | (m2 displayed-month) | |
211 | (y2 displayed-year)) | |
212 | (calendar-increment-month m1 y1 -1) | |
213 | (calendar-increment-month m2 y2 1) | |
214 | (calendar-in-read-only-buffer lunar-phases-buffer | |
215 | (calendar-set-mode-line | |
216 | (if (= y1 y2) | |
217 | (format "Phases of the Moon from %s to %s, %d%%-" | |
218 | (calendar-month-name m1) (calendar-month-name m2) y2) | |
219 | (format "Phases of the Moon from %s, %d to %s, %d%%-" | |
220 | (calendar-month-name m1) y1 (calendar-month-name m2) y2))) | |
221 | (insert | |
222 | (mapconcat | |
223 | (lambda (x) | |
b4deec2e GM |
224 | (format "%s: %s %s" (calendar-date-string (car x)) |
225 | (lunar-phase-name (nth 2 x)) | |
226 | (cadr x))) | |
dc67263c GM |
227 | (lunar-phase-list m1 y1) "\n"))) |
228 | (message "Computing phases of the moon...done")))) | |
7e1dae73 | 229 | |
273fcc9b GM |
230 | ;;;###cal-autoload |
231 | (define-obsolete-function-alias 'calendar-phases-of-moon | |
232 | 'calendar-lunar-phases "23.1") | |
233 | ||
7e1dae73 | 234 | ;;;###autoload |
273fcc9b | 235 | (defun lunar-phases (&optional arg) |
7e1dae73 | 236 | "Display the quarters of the moon for last month, this month, and next month. |
f3924c53 | 237 | If called with an optional prefix argument ARG, prompts for month and year. |
7e1dae73 JB |
238 | This function is suitable for execution in a .emacs file." |
239 | (interactive "P") | |
240 | (save-excursion | |
9c0b9187 | 241 | (let* ((date (if arg (calendar-read-date t) |
cc4879d2 | 242 | (calendar-current-date))) |
e803eab7 GM |
243 | (displayed-month (calendar-extract-month date)) |
244 | (displayed-year (calendar-extract-year date))) | |
273fcc9b GM |
245 | (calendar-lunar-phases)))) |
246 | ||
247 | ;;;###autoload | |
248 | (define-obsolete-function-alias 'phases-of-moon 'lunar-phases "23.1") | |
7e1dae73 | 249 | |
9c0b9187 GM |
250 | (defvar date) |
251 | ||
8c34d83e | 252 | ;; To be called from diary-list-sexp-entries, where DATE is bound. |
9c0b9187 | 253 | |
fb97eeac | 254 | ;;;###diary-autoload |
273fcc9b | 255 | (defun diary-lunar-phases (&optional mark) |
9c0b9187 | 256 | "Moon phases diary entry. |
a1506d29 | 257 | An optional parameter MARK specifies a face or single-character string to |
e0ab9b68 | 258 | use when highlighting the day in the calendar." |
b4deec2e | 259 | (let* ((index (lunar-index date)) |
7e1dae73 JB |
260 | (phase (lunar-phase index))) |
261 | (while (calendar-date-compare phase (list date)) | |
9c0b9187 GM |
262 | (setq index (1+ index) |
263 | phase (lunar-phase index))) | |
7e1dae73 | 264 | (if (calendar-date-equal (car phase) date) |
9c0b9187 GM |
265 | (cons mark (concat (lunar-phase-name (nth 2 phase)) " " |
266 | (cadr phase)))))) | |
7e1dae73 | 267 | |
273fcc9b GM |
268 | ;;;###diary-autoload |
269 | (define-obsolete-function-alias 'diary-phases-of-moon | |
270 | 'diary-lunar-phases "23.1") | |
271 | ||
9c0b9187 GM |
272 | ;; For the Chinese calendar the calculations for the new moon need to be more |
273 | ;; accurate than those above, so we use more terms in the approximation. | |
8a45b040 ER |
274 | (defun lunar-new-moon-time (k) |
275 | "Astronomical (Julian) day number of K th new moon." | |
276 | (let* ((T (/ k 1236.85)) | |
71ea27ee GM |
277 | (T2 (* T T)) |
278 | (T3 (* T T T)) | |
279 | (T4 (* T2 T2)) | |
280 | (JDE (+ 2451550.09765 | |
281 | (* 29.530588853 k) | |
282 | (* 0.0001337 T2) | |
283 | (* -0.000000150 T3) | |
284 | (* 0.00000000073 T4))) | |
285 | (E (- 1 (* 0.002516 T) (* 0.0000074 T2))) | |
286 | (sun-anomaly (+ 2.5534 | |
287 | (* 29.10535669 k) | |
288 | (* -0.0000218 T2) | |
289 | (* -0.00000011 T3))) | |
290 | (moon-anomaly (+ 201.5643 | |
291 | (* 385.81693528 k) | |
292 | (* 0.0107438 T2) | |
293 | (* 0.00001239 T3) | |
294 | (* -0.000000058 T4))) | |
295 | (moon-argument (+ 160.7108 | |
296 | (* 390.67050274 k) | |
297 | (* -0.0016341 T2) | |
298 | (* -0.00000227 T3) | |
299 | (* 0.000000011 T4))) | |
300 | (omega (+ 124.7746 | |
301 | (* -1.56375580 k) | |
302 | (* 0.0020691 T2) | |
303 | (* 0.00000215 T3))) | |
304 | (A1 (+ 299.77 (* 0.107408 k) (* -0.009173 T2))) | |
305 | (A2 (+ 251.88 (* 0.016321 k))) | |
306 | (A3 (+ 251.83 (* 26.641886 k))) | |
307 | (A4 (+ 349.42 (* 36.412478 k))) | |
308 | (A5 (+ 84.66 (* 18.206239 k))) | |
309 | (A6 (+ 141.74 (* 53.303771 k))) | |
310 | (A7 (+ 207.14 (* 2.453732 k))) | |
311 | (A8 (+ 154.84 (* 7.306860 k))) | |
312 | (A9 (+ 34.52 (* 27.261239 k))) | |
313 | (A10 (+ 207.19 (* 0.121824 k))) | |
314 | (A11 (+ 291.34 (* 1.844379 k))) | |
315 | (A12 (+ 161.72 (* 24.198154 k))) | |
316 | (A13 (+ 239.56 (* 25.513099 k))) | |
317 | (A14 (+ 331.55 (* 3.592518 k))) | |
318 | (correction | |
9c0b9187 GM |
319 | (+ (* -0.40720 (solar-sin-degrees moon-anomaly)) |
320 | (* 0.17241 E (solar-sin-degrees sun-anomaly)) | |
321 | (* 0.01608 (solar-sin-degrees (* 2 moon-anomaly))) | |
322 | (* 0.01039 (solar-sin-degrees (* 2 moon-argument))) | |
323 | (* 0.00739 E (solar-sin-degrees (- moon-anomaly sun-anomaly))) | |
324 | (* -0.00514 E (solar-sin-degrees (+ moon-anomaly sun-anomaly))) | |
325 | (* 0.00208 E E (solar-sin-degrees (* 2 sun-anomaly))) | |
326 | (* -0.00111 (solar-sin-degrees | |
327 | (- moon-anomaly (* 2 moon-argument)))) | |
328 | (* -0.00057 (solar-sin-degrees | |
329 | (+ moon-anomaly (* 2 moon-argument)))) | |
330 | (* 0.00056 E (solar-sin-degrees | |
331 | (+ (* 2 moon-anomaly) sun-anomaly))) | |
332 | (* -0.00042 (solar-sin-degrees (* 3 moon-anomaly))) | |
333 | (* 0.00042 E (solar-sin-degrees | |
334 | (+ sun-anomaly (* 2 moon-argument)))) | |
335 | (* 0.00038 E (solar-sin-degrees | |
336 | (- sun-anomaly (* 2 moon-argument)))) | |
337 | (* -0.00024 E (solar-sin-degrees | |
338 | (- (* 2 moon-anomaly) sun-anomaly))) | |
339 | (* -0.00017 (solar-sin-degrees omega)) | |
340 | (* -0.00007 (solar-sin-degrees | |
341 | (+ moon-anomaly (* 2 sun-anomaly)))) | |
342 | (* 0.00004 (solar-sin-degrees | |
343 | (- (* 2 moon-anomaly) (* 2 moon-argument)))) | |
344 | (* 0.00004 (solar-sin-degrees (* 3 sun-anomaly))) | |
345 | (* 0.00003 (solar-sin-degrees (+ moon-anomaly sun-anomaly | |
346 | (* -2 moon-argument)))) | |
347 | (* 0.00003 (solar-sin-degrees | |
348 | (+ (* 2 moon-anomaly) (* 2 moon-argument)))) | |
349 | (* -0.00003 (solar-sin-degrees (+ moon-anomaly sun-anomaly | |
350 | (* 2 moon-argument)))) | |
351 | (* 0.00003 (solar-sin-degrees (- moon-anomaly sun-anomaly | |
352 | (* -2 moon-argument)))) | |
353 | (* -0.00002 (solar-sin-degrees (- moon-anomaly sun-anomaly | |
354 | (* 2 moon-argument)))) | |
355 | (* -0.00002 (solar-sin-degrees | |
356 | (+ (* 3 moon-anomaly) sun-anomaly))) | |
357 | (* 0.00002 (solar-sin-degrees (* 4 moon-anomaly))))) | |
71ea27ee | 358 | (additional |
9c0b9187 GM |
359 | (+ (* 0.000325 (solar-sin-degrees A1)) |
360 | (* 0.000165 (solar-sin-degrees A2)) | |
361 | (* 0.000164 (solar-sin-degrees A3)) | |
362 | (* 0.000126 (solar-sin-degrees A4)) | |
363 | (* 0.000110 (solar-sin-degrees A5)) | |
364 | (* 0.000062 (solar-sin-degrees A6)) | |
365 | (* 0.000060 (solar-sin-degrees A7)) | |
366 | (* 0.000056 (solar-sin-degrees A8)) | |
367 | (* 0.000047 (solar-sin-degrees A9)) | |
368 | (* 0.000042 (solar-sin-degrees A10)) | |
369 | (* 0.000040 (solar-sin-degrees A11)) | |
370 | (* 0.000037 (solar-sin-degrees A12)) | |
371 | (* 0.000035 (solar-sin-degrees A13)) | |
372 | (* 0.000023 (solar-sin-degrees A14)))) | |
71ea27ee | 373 | (newJDE (+ JDE correction additional))) |
8a45b040 ER |
374 | (+ newJDE |
375 | (- (solar-ephemeris-correction | |
e803eab7 | 376 | (calendar-extract-year |
8a45b040 | 377 | (calendar-gregorian-from-absolute |
5c645a20 | 378 | (floor (calendar-astro-to-absolute newJDE)))))) |
8a45b040 ER |
379 | (/ calendar-time-zone 60.0 24.0)))) |
380 | ||
381 | (defun lunar-new-moon-on-or-after (d) | |
f3924c53 GM |
382 | "Julian day number of first new moon on or after Julian day number D. |
383 | The fractional part is the time of day. | |
8a45b040 | 384 | |
7b96378f | 385 | The date and time are local time, including any daylight saving rules, |
9c0b9187 GM |
386 | as governed by the values of `calendar-daylight-savings-starts', |
387 | `calendar-daylight-savings-starts-time', `calendar-daylight-savings-ends', | |
388 | `calendar-daylight-savings-ends-time', `calendar-daylight-time-offset', and | |
389 | `calendar-time-zone'." | |
8a45b040 | 390 | (let* ((date (calendar-gregorian-from-absolute |
5c645a20 | 391 | (floor (calendar-astro-to-absolute d)))) |
e803eab7 | 392 | (year (+ (calendar-extract-year date) |
71ea27ee | 393 | (/ (calendar-day-number date) 365.25))) |
b4deec2e | 394 | (k (floor (* (- year 2000.0) lunar-cycles-per-year))) |
4bd7ad5f GM |
395 | (date (lunar-new-moon-time k)) |
396 | (a-date (progn | |
397 | (while (< date d) | |
398 | (setq k (1+ k) | |
399 | date (lunar-new-moon-time k))) | |
5c645a20 | 400 | (calendar-astro-to-absolute date))) |
4bd7ad5f GM |
401 | (time (* 24 (- a-date (truncate a-date)))) |
402 | (date (calendar-gregorian-from-absolute (truncate a-date))) | |
403 | (adj (dst-adjust-time date time))) | |
404 | (calendar-astro-from-absolute | |
405 | (+ (calendar-absolute-from-gregorian (car adj)) | |
406 | (/ (cadr adj) 24.0))))) | |
8a45b040 | 407 | |
7e1dae73 JB |
408 | (provide 'lunar) |
409 | ||
410 | ;;; lunar.el ends here |