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a47a5be5 RS |
1 | ;;; Timezone package for GNU Emacs |
2 | ||
aa56d805 RS |
3 | ;; Copyright (C) 1990, 1991, 1992, 1993 Free Software Foundation, Inc. |
4 | ||
5 | ;;; Author: Masanobu Umeda | |
6 | ;;; Maintainer: umerin@mse.kyutech.ac.jp | |
a47a5be5 RS |
7 | |
8 | ;; This file is part of GNU Emacs. | |
9 | ||
10 | ;; GNU Emacs is free software; you can redistribute it and/or modify | |
11 | ;; it under the terms of the GNU General Public License as published by | |
12 | ;; the Free Software Foundation; either version 2, or (at your option) | |
13 | ;; any later version. | |
14 | ||
15 | ;; GNU Emacs is distributed in the hope that it will be useful, | |
16 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
18 | ;; GNU General Public License for more details. | |
19 | ||
20 | ;; You should have received a copy of the GNU General Public License | |
21 | ;; along with GNU Emacs; see the file COPYING. If not, write to | |
22 | ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. | |
23 | ||
24 | ;;; Code: | |
25 | ||
26 | (provide 'timezone) | |
27 | ||
28 | (defvar timezone-world-timezones | |
29 | '(("PST" . -800) | |
30 | ("PDT" . -700) | |
31 | ("MST" . -700) | |
32 | ("MDT" . -600) | |
33 | ("CST" . -600) | |
34 | ("CDT" . -500) | |
35 | ("EST" . -500) | |
36 | ("EDT" . -400) | |
37 | ("AST" . -400) ;by <clamen@CS.CMU.EDU> | |
38 | ("NST" . -330) ;by <clamen@CS.CMU.EDU> | |
39 | ("GMT" . +000) | |
40 | ("BST" . +100) | |
41 | ("MET" . +100) | |
42 | ("EET" . +200) | |
43 | ("JST" . +900) | |
44 | ("GMT+1" . +100) ("GMT+2" . +200) ("GMT+3" . +300) | |
45 | ("GMT+4" . +400) ("GMT+5" . +500) ("GMT+6" . +600) | |
46 | ("GMT+7" . +700) ("GMT+8" . +800) ("GMT+9" . +900) | |
47 | ("GMT+10" . +1000) ("GMT+11" . +1100) ("GMT+12" . +1200) ("GMT+13" . +1300) | |
48 | ("GMT-1" . -100) ("GMT-2" . -200) ("GMT-3" . -300) | |
49 | ("GMT-4" . -400) ("GMT-5" . -500) ("GMT-6" . -600) | |
50 | ("GMT-7" . -700) ("GMT-8" . -800) ("GMT-9" . -900) | |
51 | ("GMT-10" . -1000) ("GMT-11" . -1100) ("GMT-12" . -1200)) | |
d51c3cda RS |
52 | "*Time differentials of timezone from GMT in +-HHMM form. |
53 | This list is obsolescent, and is present only for backwards compatibility, | |
54 | because time zone names are ambiguous in practice. | |
55 | Use `current-time-zone' instead.") | |
a47a5be5 RS |
56 | |
57 | (defvar timezone-months-assoc | |
58 | '(("JAN" . 1)("FEB" . 2)("MAR" . 3) | |
59 | ("APR" . 4)("MAY" . 5)("JUN" . 6) | |
60 | ("JUL" . 7)("AUG" . 8)("SEP" . 9) | |
61 | ("OCT" . 10)("NOV" . 11)("DEC" . 12)) | |
62 | "Alist of first three letters of a month and its numerical representation.") | |
63 | ||
64 | (defun timezone-make-date-arpa-standard (date &optional local timezone) | |
65 | "Convert DATE to an arpanet standard date. | |
d51c3cda RS |
66 | Optional 1st argument LOCAL specifies the default local timezone of the DATE; |
67 | if nil, GMT is assumed. | |
68 | Optional 2nd argument TIMEZONE specifies a time zone to be represented in; | |
69 | if nil, the local time zone is assumed." | |
70 | (let ((new (timezone-fix-time date local timezone))) | |
a47a5be5 RS |
71 | (timezone-make-arpa-date (aref new 0) (aref new 1) (aref new 2) |
72 | (timezone-make-time-string | |
73 | (aref new 3) (aref new 4) (aref new 5)) | |
d51c3cda | 74 | (aref new 6)) |
a47a5be5 RS |
75 | )) |
76 | ||
77 | (defun timezone-make-date-sortable (date &optional local timezone) | |
78 | "Convert DATE to a sortable date string. | |
d51c3cda RS |
79 | Optional 1st argument LOCAL specifies the default local timezone of the DATE; |
80 | if nil, GMT is assumed. | |
81 | Optional 2nd argument TIMEZONE specifies a timezone to be represented in; | |
82 | if nil, the local time zone is assumed." | |
83 | (let ((new (timezone-fix-time date local timezone))) | |
a47a5be5 RS |
84 | (timezone-make-sortable-date (aref new 0) (aref new 1) (aref new 2) |
85 | (timezone-make-time-string | |
86 | (aref new 3) (aref new 4) (aref new 5))) | |
87 | )) | |
88 | ||
89 | \f | |
90 | ;; | |
91 | ;; Parsers and Constructors of Date and Time | |
92 | ;; | |
93 | ||
94 | (defun timezone-make-arpa-date (year month day time &optional timezone) | |
95 | "Make arpanet standard date string from YEAR, MONTH, DAY, and TIME. | |
96 | Optional argument TIMEZONE specifies a time zone." | |
d51c3cda RS |
97 | (let ((zone |
98 | (if (listp timezone) | |
99 | (let* ((m (timezone-zone-to-minute timezone)) | |
100 | (absm (if (< m 0) (- m) m))) | |
101 | (format "%c%02d%02d" | |
102 | (if (< m 0) ?- ?+) (/ absm 60) (% absm 60))) | |
103 | timezone))) | |
104 | (format "%02d %s %04d %s %s" | |
105 | day | |
106 | (capitalize (car (rassq month timezone-months-assoc))) | |
107 | year | |
108 | time | |
109 | zone))) | |
a47a5be5 RS |
110 | |
111 | (defun timezone-make-sortable-date (year month day time) | |
112 | "Make sortable date string from YEAR, MONTH, DAY, and TIME." | |
113 | (format "%4d%02d%02d%s" | |
d51c3cda | 114 | year month day time)) |
a47a5be5 RS |
115 | |
116 | (defun timezone-make-time-string (hour minute second) | |
117 | "Make time string from HOUR, MINUTE, and SECOND." | |
118 | (format "%02d:%02d:%02d" hour minute second)) | |
119 | ||
120 | (defun timezone-parse-date (date) | |
6b77e539 RS |
121 | "Parse DATE and return a vector [YEAR MONTH DAY TIME TIMEZONE]. |
122 | 19 is prepended to year if necessary. Timezone may be nil if nothing. | |
123 | Understands the following styles: | |
a47a5be5 RS |
124 | (1) 14 Apr 89 03:20[:12] [GMT] |
125 | (2) Fri, 17 Mar 89 4:01[:33] [GMT] | |
126 | (3) Mon Jan 16 16:12[:37] [GMT] 1989 | |
6b77e539 RS |
127 | (4) 6 May 1992 1641-JST (Wednesday) |
128 | (5) 22-AUG-1993 10:59:12.82" | |
a47a5be5 RS |
129 | (let ((date (or date "")) |
130 | (year nil) | |
131 | (month nil) | |
132 | (day nil) | |
133 | (time nil) | |
134 | (zone nil)) ;This may be nil. | |
135 | (cond ((string-match | |
136 | "\\([0-9]+\\)[ \t]+\\([^ \t,]+\\)[ \t]+\\([0-9]+\\)[ \t]+\\([0-9]+:[0-9:]+\\)[ \t]*\\'" date) | |
137 | ;; Styles: (1) and (2) without timezone | |
138 | (setq year 3 month 2 day 1 time 4 zone nil)) | |
139 | ((string-match | |
140 | "\\([0-9]+\\)[ \t]+\\([^ \t,]+\\)[ \t]+\\([0-9]+\\)[ \t]+\\([0-9]+:[0-9:]+\\)[ \t]*\\([-+a-zA-Z0-9]+\\)" date) | |
141 | ;; Styles: (1) and (2) with timezone and buggy timezone | |
142 | (setq year 3 month 2 day 1 time 4 zone 5)) | |
143 | ((string-match | |
144 | "\\([^ \t,]+\\)[ \t]+\\([0-9]+\\)[ \t]+\\([0-9]+:[0-9:]+\\)[ \t]+\\([0-9]+\\)" date) | |
145 | ;; Styles: (3) without timezone | |
146 | (setq year 4 month 1 day 2 time 3 zone nil)) | |
147 | ((string-match | |
148 | "\\([^ \t,]+\\)[ \t]+\\([0-9]+\\)[ \t]+\\([0-9]+:[0-9:]+\\)[ \t]+\\([-+a-zA-Z0-9]+\\)[ \t]+\\([0-9]+\\)" date) | |
6b77e539 | 149 | ;; Styles: (3) with timezone |
a47a5be5 RS |
150 | (setq year 5 month 1 day 2 time 3 zone 4)) |
151 | ((string-match | |
152 | "\\([0-9]+\\)[ \t]+\\([^ \t,]+\\)[ \t]+\\([0-9]+\\)[ \t]+\\([0-9]+\\)[ \t]*\\([-+a-zA-Z0-9]+\\)" date) | |
153 | ;; Styles: (4) with timezone | |
154 | (setq year 3 month 2 day 1 time 4 zone 5)) | |
6b77e539 RS |
155 | ((string-match |
156 | "\\([0-9]+\\)-\\([A-Za-z]+\\)-\\([0-9]+\\)[ \t]+\\([0-9]+:[0-9]+:[0-9]+\\)\\.[0-9]+" date) | |
157 | ;; Styles: (5) without timezone. | |
158 | (setq year 3 month 2 day 1 time 4 zone nil)) | |
a47a5be5 RS |
159 | ) |
160 | (if year | |
161 | (progn | |
162 | (setq year | |
163 | (substring date (match-beginning year) (match-end year))) | |
164 | ;; It is now Dec 1992. 8 years before the end of the World. | |
165 | (if (< (length year) 4) | |
166 | (setq year (concat "19" (substring year -2 nil)))) | |
167 | (setq month | |
168 | (int-to-string | |
169 | (cdr | |
170 | (assoc | |
171 | (upcase | |
172 | ;; Don't use `match-end' in order to take 3 | |
173 | ;; letters from the beginning. | |
174 | (substring date | |
175 | (match-beginning month) | |
176 | (+ (match-beginning month) 3))) | |
177 | timezone-months-assoc)))) | |
178 | (setq day | |
179 | (substring date (match-beginning day) (match-end day))) | |
180 | (setq time | |
181 | (substring date (match-beginning time) (match-end time))))) | |
182 | (if zone | |
183 | (setq zone | |
184 | (substring date (match-beginning zone) (match-end zone)))) | |
185 | ;; Return a vector. | |
186 | (if year | |
187 | (vector year month day time zone) | |
188 | (vector "0" "0" "0" "0" nil)) | |
189 | )) | |
190 | ||
191 | (defun timezone-parse-time (time) | |
192 | "Parse TIME (HH:MM:SS) and return a vector [hour minute second]. | |
193 | Recognize HH:MM:SS, HH:MM, HHMMSS, HHMM." | |
194 | (let ((time (or time "")) | |
195 | (hour nil) | |
196 | (minute nil) | |
197 | (second nil)) | |
198 | (cond ((string-match "\\`\\([0-9]+\\):\\([0-9]+\\):\\([0-9]+\\)\\'" time) | |
199 | ;; HH:MM:SS | |
200 | (setq hour 1 minute 2 second 3)) | |
201 | ((string-match "\\`\\([0-9]+\\):\\([0-9]+\\)\\'" time) | |
202 | ;; HH:MM | |
203 | (setq hour 1 minute 2 second nil)) | |
204 | ((string-match "\\`\\([0-9][0-9]\\)\\([0-9][0-9]\\)\\([0-9][0-9]\\)\\'" time) | |
205 | ;; HHMMSS | |
206 | (setq hour 1 minute 2 second 3)) | |
207 | ((string-match "\\`\\([0-9][0-9]\\)\\([0-9][0-9]\\)\\'" time) | |
208 | ;; HHMM | |
209 | (setq hour 1 minute 2 second nil)) | |
210 | ) | |
211 | ;; Return [hour minute second] | |
212 | (vector | |
213 | (if hour | |
214 | (substring time (match-beginning hour) (match-end hour)) "0") | |
215 | (if minute | |
216 | (substring time (match-beginning minute) (match-end minute)) "0") | |
217 | (if second | |
218 | (substring time (match-beginning second) (match-end second)) "0")) | |
219 | )) | |
220 | ||
221 | \f | |
222 | ;; Miscellaneous | |
223 | ||
224 | (defun timezone-zone-to-minute (timezone) | |
d51c3cda RS |
225 | "Translate TIMEZONE to an integer minute offset from GMT. |
226 | TIMEZONE can be a cons cell containing the output of current-time-zone, | |
227 | or an integer of the form +-HHMM, or a time zone name." | |
228 | (cond | |
229 | ((consp timezone) | |
230 | (/ (car timezone) 60)) | |
231 | (timezone | |
a47a5be5 RS |
232 | (progn |
233 | (setq timezone | |
234 | (or (cdr (assoc (upcase timezone) timezone-world-timezones)) | |
235 | ;; +900 | |
236 | timezone)) | |
237 | (if (stringp timezone) | |
238 | (setq timezone (string-to-int timezone))) | |
239 | ;; Taking account of minute in timezone. | |
240 | ;; HHMM -> MM | |
9b1868cc | 241 | (let* ((abszone (abs timezone)) |
a47a5be5 | 242 | (minutes (+ (* 60 (/ abszone 100)) (% abszone 100)))) |
d51c3cda RS |
243 | (if (< timezone 0) (- minutes) minutes)))) |
244 | (t 0))) | |
245 | ||
246 | (defun timezone-time-from-absolute (date seconds) | |
247 | "Compute the UTC time equivalent to DATE at time SECONDS after midnight. | |
248 | Return a list suitable as an argument to current-time-zone, | |
249 | or nil if the date cannot be thus represented. | |
250 | DATE is the number of days elapsed since the (imaginary) | |
251 | Gregorian date Sunday, December 31, 1 BC." | |
252 | (let* ((current-time-origin 719162) | |
253 | ;; (timezone-absolute-from-gregorian 1 1 1970) | |
254 | (days (- date current-time-origin)) | |
255 | (seconds-per-day (float 86400)) | |
256 | (seconds (+ seconds (* days seconds-per-day))) | |
257 | (current-time-arithmetic-base (float 65536)) | |
258 | (hi (floor (/ seconds current-time-arithmetic-base))) | |
259 | (hibase (* hi current-time-arithmetic-base)) | |
260 | (lo (floor (- seconds hibase)))) | |
261 | (and (< (abs (- seconds (+ hibase lo))) 2) ;; Check for integer overflow. | |
262 | (cons hi lo)))) | |
a47a5be5 | 263 | |
d51c3cda RS |
264 | (defun timezone-time-zone-from-absolute (date seconds) |
265 | "Compute the local time zone for DATE at time SECONDS after midnight. | |
266 | Return a list in the same format as current-time-zone's result, | |
267 | or nil if the local time zone could not be computed. | |
268 | DATE is the number of days elapsed since the (imaginary) | |
269 | Gregorian date Sunday, December 31, 1 BC." | |
270 | (and (fboundp 'current-time-zone) | |
271 | (let ((utc-time (timezone-time-from-absolute date seconds))) | |
272 | (and utc-time | |
273 | (let ((zone (current-time-zone utc-time))) | |
274 | (and (car zone) zone)))))) | |
275 | ||
276 | (defun timezone-fix-time (date local timezone) | |
dce33aad | 277 | "Convert DATE (default timezone LOCAL) to YYYY-MM-DD-HH-MM-SS-ZONE vector. |
d51c3cda RS |
278 | If LOCAL is nil, it is assumed to be GMT. |
279 | If TIMEZONE is nil, use the local time zone." | |
280 | (let* ((date (timezone-parse-date date)) | |
281 | (year (string-to-int (aref date 0))) | |
282 | (year (if (< year 100) (+ year 1900) year)) | |
283 | (month (string-to-int (aref date 1))) | |
284 | (day (string-to-int (aref date 2))) | |
285 | (time (timezone-parse-time (aref date 3))) | |
286 | (hour (string-to-int (aref time 0))) | |
287 | (minute (string-to-int (aref time 1))) | |
288 | (second (string-to-int (aref time 2))) | |
289 | (local (or (aref date 4) local)) ;Use original if defined | |
290 | (timezone | |
291 | (or timezone | |
292 | (timezone-time-zone-from-absolute | |
293 | (timezone-absolute-from-gregorian month day year) | |
294 | (+ second (* 60 (+ minute (* 60 hour))))))) | |
295 | (diff (- (timezone-zone-to-minute timezone) | |
296 | (timezone-zone-to-minute local))) | |
297 | (minute (+ minute diff)) | |
9b1868cc | 298 | (hour-fix (floor minute 60))) |
a47a5be5 | 299 | (setq hour (+ hour hour-fix)) |
d51c3cda RS |
300 | (setq minute (- minute (* 60 hour-fix))) |
301 | ;; HOUR may be larger than 24 or smaller than 0. | |
302 | (cond ((<= 24 hour) ;24 -> 00 | |
303 | (setq hour (- hour 24)) | |
304 | (setq day (1+ day)) | |
305 | (if (< (timezone-last-day-of-month month year) day) | |
306 | (progn | |
307 | (setq month (1+ month)) | |
308 | (setq day 1) | |
309 | (if (< 12 month) | |
310 | (progn | |
311 | (setq month 1) | |
312 | (setq year (1+ year)) | |
313 | )) | |
314 | ))) | |
315 | ((> 0 hour) | |
316 | (setq hour (+ hour 24)) | |
317 | (setq day (1- day)) | |
318 | (if (> 1 day) | |
319 | (progn | |
320 | (setq month (1- month)) | |
321 | (if (> 1 month) | |
322 | (progn | |
323 | (setq month 12) | |
324 | (setq year (1- year)) | |
325 | )) | |
326 | (setq day (timezone-last-day-of-month month year)) | |
327 | ))) | |
328 | ) | |
329 | (vector year month day hour minute second timezone))) | |
a47a5be5 RS |
330 | |
331 | ;; Partly copied from Calendar program by Edward M. Reingold. | |
332 | ;; Thanks a lot. | |
333 | ||
334 | (defun timezone-last-day-of-month (month year) | |
335 | "The last day in MONTH during YEAR." | |
336 | (if (and (= month 2) (timezone-leap-year-p year)) | |
337 | 29 | |
338 | (aref [31 28 31 30 31 30 31 31 30 31 30 31] (1- month)))) | |
339 | ||
340 | (defun timezone-leap-year-p (year) | |
341 | "Returns t if YEAR is a Gregorian leap year." | |
342 | (or (and (zerop (% year 4)) | |
343 | (not (zerop (% year 100)))) | |
344 | (zerop (% year 400)))) | |
aa56d805 | 345 | |
d51c3cda RS |
346 | (defun timezone-day-number (month day year) |
347 | "Return the day number within the year of the date month/day/year." | |
348 | (let ((day-of-year (+ day (* 31 (1- month))))) | |
349 | (if (> month 2) | |
350 | (progn | |
351 | (setq day-of-year (- day-of-year (/ (+ 23 (* 4 month)) 10))) | |
352 | (if (timezone-leap-year-p year) | |
353 | (setq day-of-year (1+ day-of-year))))) | |
354 | day-of-year)) | |
355 | ||
356 | (defun timezone-absolute-from-gregorian (month day year) | |
357 | "The number of days between the Gregorian date 12/31/1 BC and month/day/year. | |
358 | The Gregorian date Sunday, December 31, 1 BC is imaginary." | |
359 | (+ (timezone-day-number month day year);; Days this year | |
360 | (* 365 (1- year));; + Days in prior years | |
361 | (/ (1- year) 4);; + Julian leap years | |
362 | (- (/ (1- year) 100));; - century years | |
363 | (/ (1- year) 400)));; + Gregorian leap years | |
364 | ||
aa56d805 | 365 | ;;; timezone.el ends here |