-;;; Timezone package for GNU Emacs
+;;; timezone.el --- time zone package for GNU Emacs
-;; Copyright (C) 1990, 1991, 1992, 1993 Free Software Foundation, Inc.
+;; Copyright (C) 1990, 1991, 1992, 1993, 1996, 1999, 2002, 2003,
+;; 2004, 2005, 2006 Free Software Foundation, Inc.
-;;; Author: Masanobu Umeda
-;;; Maintainer: umerin@mse.kyutech.ac.jp
+;; Author: Masanobu Umeda
+;; Maintainer: umerin@mse.kyutech.ac.jp
+;; Keywords: news
;; This file is part of GNU Emacs.
;; GNU General Public License for more details.
;; 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, 675 Mass Ave, Cambridge, MA 02139, USA.
+;; 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.
-;;; Code:
+;;; Commentary:
-(provide 'timezone)
+;;; Code:
(defvar timezone-world-timezones
'(("PST" . -800)
("EDT" . -400)
("AST" . -400) ;by <clamen@CS.CMU.EDU>
("NST" . -330) ;by <clamen@CS.CMU.EDU>
+ ("UT" . +000)
("GMT" . +000)
("BST" . +100)
("MET" . +100)
("GMT-4" . -400) ("GMT-5" . -500) ("GMT-6" . -600)
("GMT-7" . -700) ("GMT-8" . -800) ("GMT-9" . -900)
("GMT-10" . -1000) ("GMT-11" . -1100) ("GMT-12" . -1200))
- "*Time differentials of timezone from GMT in hour.")
+ "*Time differentials of timezone from GMT in +-HHMM form.
+This list is obsolescent, and is present only for backwards compatibility,
+because time zone names are ambiguous in practice.
+Use `current-time-zone' instead.")
(defvar timezone-months-assoc
'(("JAN" . 1)("FEB" . 2)("MAR" . 3)
(defun timezone-make-date-arpa-standard (date &optional local timezone)
"Convert DATE to an arpanet standard date.
-Optional 1st argumetn LOCAL specifies the default local timezone of the DATE.
-Optional 2nd argument TIMEZONE specifies a timezone to be represented in."
- (let* ((date (timezone-parse-date date))
- (year (string-to-int (aref date 0)))
- (month (string-to-int (aref date 1)))
- (day (string-to-int (aref date 2)))
- (time (timezone-parse-time (aref date 3)))
- (hour (string-to-int (aref time 0)))
- (minute (string-to-int (aref time 1)))
- (second (string-to-int (aref time 2)))
- (local (or (aref date 4) local)) ;Use original if defined
- (timezone (or timezone local))
- (diff (- (timezone-zone-to-minute timezone)
- (timezone-zone-to-minute local)))
- (new (timezone-fix-time year month day
- hour (+ minute diff) second)))
+Optional 2nd argument LOCAL specifies the default local timezone of the DATE;
+if nil, GMT is assumed.
+Optional 3rd argument TIMEZONE specifies a time zone to be represented in;
+if nil, the local time zone is assumed."
+ (let ((new (timezone-fix-time date local timezone)))
(timezone-make-arpa-date (aref new 0) (aref new 1) (aref new 2)
(timezone-make-time-string
(aref new 3) (aref new 4) (aref new 5))
- timezone)
+ (aref new 6))
))
(defun timezone-make-date-sortable (date &optional local timezone)
"Convert DATE to a sortable date string.
-Optional 1st argumetn LOCAL specifies the default local timezone of the DATE.
-Optional 2nd argument TIMEZONE specifies a timezone to be represented in."
- (let* ((date (timezone-parse-date date))
- (year (string-to-int (aref date 0)))
- (month (string-to-int (aref date 1)))
- (day (string-to-int (aref date 2)))
- (time (timezone-parse-time (aref date 3)))
- (hour (string-to-int (aref time 0)))
- (minute (string-to-int (aref time 1)))
- (second (string-to-int (aref time 2)))
- (local (or (aref date 4) local)) ;Use original if defined
- (timezone (or timezone local))
- (diff (- (timezone-zone-to-minute timezone)
- (timezone-zone-to-minute local)))
- (new (timezone-fix-time year month day
- hour (+ minute diff) second)))
+Optional 2nd argument LOCAL specifies the default local timezone of the DATE;
+if nil, GMT is assumed.
+Optional 3rd argument TIMEZONE specifies a timezone to be represented in;
+if nil, the local time zone is assumed."
+ (let ((new (timezone-fix-time date local timezone)))
(timezone-make-sortable-date (aref new 0) (aref new 1) (aref new 2)
(timezone-make-time-string
(aref new 3) (aref new 4) (aref new 5)))
(defun timezone-make-arpa-date (year month day time &optional timezone)
"Make arpanet standard date string from YEAR, MONTH, DAY, and TIME.
Optional argument TIMEZONE specifies a time zone."
- (format "%02d %s %4d %s%s"
- day
- (capitalize (car (rassq month timezone-months-assoc)))
- ;;(- year (* (/ year 100) 100)) ;1990 -> 90
- (if (< year 100) (+ year 1900) year) ;90->1990
- time
- (if timezone (concat " " timezone) "")
- ))
+ (let ((zone
+ (if (listp timezone)
+ (let* ((m (timezone-zone-to-minute timezone))
+ (absm (if (< m 0) (- m) m)))
+ (format "%c%02d%02d"
+ (if (< m 0) ?- ?+) (/ absm 60) (% absm 60)))
+ timezone)))
+ (format "%02d %s %04d %s %s"
+ day
+ (capitalize (car (rassq month timezone-months-assoc)))
+ year
+ time
+ zone)))
(defun timezone-make-sortable-date (year month day time)
"Make sortable date string from YEAR, MONTH, DAY, and TIME."
(format "%4d%02d%02d%s"
- ;;(- year (* (/ year 100) 100)) ;1990 -> 90
- (if (< year 100) (+ year 1900) year) ;90->1990
- month day time))
+ year month day time))
(defun timezone-make-time-string (hour minute second)
"Make time string from HOUR, MINUTE, and SECOND."
(format "%02d:%02d:%02d" hour minute second))
(defun timezone-parse-date (date)
- "Parse DATE and return a vector [year month day time timezone].
-19 is prepended to year if necessary. Timezone may be NIL if nothing.
-Understand the following styles:
+ "Parse DATE and return a vector [YEAR MONTH DAY TIME TIMEZONE].
+Two-digit dates are `windowed'. Those <69 have 2000 added; otherwise 1900
+is added. Three-digit dates have 1900 added.
+TIMEZONE is nil for DATEs without a zone field.
+
+Understands the following styles:
(1) 14 Apr 89 03:20[:12] [GMT]
(2) Fri, 17 Mar 89 4:01[:33] [GMT]
(3) Mon Jan 16 16:12[:37] [GMT] 1989
- (4) 6 May 1992 1641-JST (Wednesday)"
+ (4) 6 May 1992 1641-JST (Wednesday)
+ (5) 22-AUG-1993 10:59:12.82
+ (6) Thu, 11 Apr 16:17:12 91 [MET]
+ (7) Mon, 6 Jul 16:47:20 T 1992 [MET]
+ (8) 1996-06-24 21:13:12 [GMT]
+ (9) 1996-06-24 21:13-ZONE"
+ ;; Get rid of any text properties.
+ (and (stringp date)
+ (or (text-properties-at 0 date)
+ (next-property-change 0 date))
+ (setq date (copy-sequence date))
+ (set-text-properties 0 (length date) nil date))
(let ((date (or date ""))
(year nil)
(month nil)
(time nil)
(zone nil)) ;This may be nil.
(cond ((string-match
+ "\\([0-9]+\\)[ \t]+\\([^ \t,]+\\)[ \t]+\\([0-9]+\\)[ \t]+\\([0-9]+:[0-9:]+\\)[ \t]+\\([-+a-zA-Z0-9]+\\)" date)
+ ;; Styles: (1) and (2) with timezone and buggy timezone
+ ;; This is most common in mail and news,
+ ;; so it is worth trying first.
+ (setq year 3 month 2 day 1 time 4 zone 5))
+ ((string-match
"\\([0-9]+\\)[ \t]+\\([^ \t,]+\\)[ \t]+\\([0-9]+\\)[ \t]+\\([0-9]+:[0-9:]+\\)[ \t]*\\'" date)
;; Styles: (1) and (2) without timezone
(setq year 3 month 2 day 1 time 4 zone nil))
((string-match
- "\\([0-9]+\\)[ \t]+\\([^ \t,]+\\)[ \t]+\\([0-9]+\\)[ \t]+\\([0-9]+:[0-9:]+\\)[ \t]*\\([-+a-zA-Z0-9]+\\)" date)
- ;; Styles: (1) and (2) with timezone and buggy timezone
- (setq year 3 month 2 day 1 time 4 zone 5))
+ "\\([^ \t,]+\\),[ \t]+\\([0-9]+\\)[ \t]+\\([^ \t,]+\\)[ \t]+\\([0-9]+:[0-9:]+\\)[ \t]+\\(T[ \t]+\\|\\)\\([0-9]+\\)[ \t]*\\'" date)
+ ;; Styles: (6) and (7) without timezone
+ (setq year 6 month 3 day 2 time 4 zone nil))
+ ((string-match
+ "\\([^ \t,]+\\),[ \t]+\\([0-9]+\\)[ \t]+\\([^ \t,]+\\)[ \t]+\\([0-9]+:[0-9:]+\\)[ \t]+\\(T[ \t]+\\|\\)\\([0-9]+\\)[ \t]*\\([-+a-zA-Z0-9]+\\)" date)
+ ;; Styles: (6) and (7) with timezone and buggy timezone
+ (setq year 6 month 3 day 2 time 4 zone 7))
((string-match
"\\([^ \t,]+\\)[ \t]+\\([0-9]+\\)[ \t]+\\([0-9]+:[0-9:]+\\)[ \t]+\\([0-9]+\\)" date)
;; Styles: (3) without timezone
(setq year 4 month 1 day 2 time 3 zone nil))
((string-match
"\\([^ \t,]+\\)[ \t]+\\([0-9]+\\)[ \t]+\\([0-9]+:[0-9:]+\\)[ \t]+\\([-+a-zA-Z0-9]+\\)[ \t]+\\([0-9]+\\)" date)
- ;; Styles: (3) with timezoen
+ ;; Styles: (3) with timezone
(setq year 5 month 1 day 2 time 3 zone 4))
((string-match
"\\([0-9]+\\)[ \t]+\\([^ \t,]+\\)[ \t]+\\([0-9]+\\)[ \t]+\\([0-9]+\\)[ \t]*\\([-+a-zA-Z0-9]+\\)" date)
;; Styles: (4) with timezone
(setq year 3 month 2 day 1 time 4 zone 5))
+ ((string-match
+ "\\([0-9]+\\)-\\([A-Za-z]+\\)-\\([0-9]+\\)[ \t]+\\([0-9]+:[0-9]+:[0-9]+\\)\\(\\.[0-9]+\\)?[ \t]+\\([-+a-zA-Z0-9]+\\)" date)
+ ;; Styles: (5) with timezone.
+ (setq year 3 month 2 day 1 time 4 zone 6))
+ ((string-match
+ "\\([0-9]+\\)-\\([A-Za-z]+\\)-\\([0-9]+\\)[ \t]+\\([0-9]+:[0-9]+:[0-9]+\\)\\(\\.[0-9]+\\)?" date)
+ ;; Styles: (5) without timezone.
+ (setq year 3 month 2 day 1 time 4 zone nil))
+ ((string-match
+ "\\([0-9]+\\)-\\([0-9]+\\)-\\([0-9]+\\)[ \t]+\\([0-9]+:[0-9]+:[0-9]+\\)[ \t]+\\([-+a-zA-Z0-9]+\\)" date)
+ ;; Styles: (8) with timezone.
+ (setq year 1 month 2 day 3 time 4 zone 5))
+ ((string-match
+ "\\([0-9]+\\)-\\([0-9]+\\)-\\([0-9]+\\)[T \t]+\\([0-9]+:[0-9]+\\)[ \t]+\\([-+a-zA-Z0-9:]+\\)" date)
+ ;; Styles: (8) with timezone with a colon in it.
+ (setq year 1 month 2 day 3 time 4 zone 5))
+ ((string-match
+ "\\([0-9]+\\)-\\([0-9]+\\)-\\([0-9]+\\)[T \t]+\\([0-9]+:[0-9]+:[0-9]+\\)" date)
+ ;; Styles: (8) without timezone.
+ (setq year 1 month 2 day 3 time 4 zone nil))
)
- (if year
- (progn
- (setq year
- (substring date (match-beginning year) (match-end year)))
- ;; It is now Dec 1992. 8 years before the end of the World.
- (if (< (length year) 4)
- (setq year (concat "19" (substring year -2 nil))))
- (setq month
- (int-to-string
- (cdr
- (assoc
- (upcase
- ;; Don't use `match-end' in order to take 3
- ;; letters from the beginning.
- (substring date
- (match-beginning month)
- (+ (match-beginning month) 3)))
- timezone-months-assoc))))
- (setq day
- (substring date (match-beginning day) (match-end day)))
- (setq time
- (substring date (match-beginning time) (match-end time)))))
- (if zone
- (setq zone
- (substring date (match-beginning zone) (match-end zone))))
+ (when year
+ (setq year (match-string year date))
+ ;; Guess ambiguous years. Assume years < 69 don't predate the
+ ;; Unix Epoch, so are 2000+. Three-digit years are assumed to
+ ;; be relative to 1900.
+ (if (< (length year) 4)
+ (let ((y (string-to-number year)))
+ (if (< y 69)
+ (setq y (+ y 100)))
+ (setq year (int-to-string (+ 1900 y)))))
+ (setq month
+ (if (= (aref date (+ (match-beginning month) 2)) ?-)
+ ;; Handle numeric months, spanning exactly two digits.
+ (substring date
+ (match-beginning month)
+ (+ (match-beginning month) 2))
+ (let* ((string (substring date
+ (match-beginning month)
+ (+ (match-beginning month) 3)))
+ (monthnum
+ (cdr (assoc (upcase string) timezone-months-assoc))))
+ (if monthnum
+ (int-to-string monthnum)))))
+ (setq day (match-string day date))
+ (setq time (match-string time date)))
+ (if zone (setq zone (match-string zone date)))
;; Return a vector.
- (if year
+ (if (and year month)
(vector year month day time zone)
- (vector "0" "0" "0" "0" nil))
- ))
+ (vector "0" "0" "0" "0" nil))))
(defun timezone-parse-time (time)
"Parse TIME (HH:MM:SS) and return a vector [hour minute second].
Recognize HH:MM:SS, HH:MM, HHMMSS, HHMM."
(let ((time (or time ""))
- (hour nil)
- (minute nil)
- (second nil))
+ hour minute second)
(cond ((string-match "\\`\\([0-9]+\\):\\([0-9]+\\):\\([0-9]+\\)\\'" time)
;; HH:MM:SS
(setq hour 1 minute 2 second 3))
)
;; Return [hour minute second]
(vector
- (if hour
- (substring time (match-beginning hour) (match-end hour)) "0")
- (if minute
- (substring time (match-beginning minute) (match-end minute)) "0")
- (if second
- (substring time (match-beginning second) (match-end second)) "0"))
- ))
+ (if hour (match-string hour time) "0")
+ (if minute (match-string minute time) "0")
+ (if second (match-string second time) "0"))))
\f
;; Miscellaneous
(defun timezone-zone-to-minute (timezone)
- "Translate TIMEZONE (in zone name or integer) to integer minute."
- (if timezone
+ "Translate TIMEZONE to an integer minute offset from GMT.
+TIMEZONE can be a cons cell containing the output of current-time-zone,
+or an integer of the form +-HHMM, or a time zone name."
+ (cond
+ ((consp timezone)
+ (/ (car timezone) 60))
+ (timezone
(progn
(setq timezone
(or (cdr (assoc (upcase timezone) timezone-world-timezones))
;; +900
timezone))
(if (stringp timezone)
- (setq timezone (string-to-int timezone)))
+ (setq timezone (string-to-number timezone)))
;; Taking account of minute in timezone.
;; HHMM -> MM
- ;;(+ (* 60 (/ timezone 100)) (% timezone 100))
- ;; ANSI C compliance about truncation of integer division
- ;; by eggert@twinsun.com (Paul Eggert)
- (let* ((abszone (max timezone (- timezone)))
+ (let* ((abszone (abs timezone))
(minutes (+ (* 60 (/ abszone 100)) (% abszone 100))))
- (if (< timezone 0) (- minutes) minutes)))
- 0))
+ (if (< timezone 0) (- minutes) minutes))))
+ (t 0)))
+
+(defun timezone-time-from-absolute (date seconds)
+ "Compute the UTC time equivalent to DATE at time SECONDS after midnight.
+Return a list suitable as an argument to current-time-zone,
+or nil if the date cannot be thus represented.
+DATE is the number of days elapsed since the (imaginary)
+Gregorian date Sunday, December 31, 1 BC."
+ (let* ((current-time-origin 719163)
+ ;; (timezone-absolute-from-gregorian 1 1 1970)
+ (days (- date current-time-origin))
+ (seconds-per-day (float 86400))
+ (seconds (+ seconds (* days seconds-per-day)))
+ (current-time-arithmetic-base (float 65536))
+ (hi (floor (/ seconds current-time-arithmetic-base)))
+ (hibase (* hi current-time-arithmetic-base))
+ (lo (floor (- seconds hibase))))
+ (and (< (abs (- seconds (+ hibase lo))) 2) ;; Check for integer overflow.
+ (cons hi lo))))
+
+(defun timezone-time-zone-from-absolute (date seconds)
+ "Compute the local time zone for DATE at time SECONDS after midnight.
+Return a list in the same format as current-time-zone's result,
+or nil if the local time zone could not be computed.
+DATE is the number of days elapsed since the (imaginary)
+Gregorian date Sunday, December 31, 1 BC."
+ (and (fboundp 'current-time-zone)
+ (let ((utc-time (timezone-time-from-absolute date seconds)))
+ (and utc-time
+ (let ((zone (current-time-zone utc-time)))
+ (and (car zone) zone))))))
-(defun timezone-fix-time (year month day hour minute second)
- "Fix date and time."
- ;; MINUTE may be larger than 60 or smaller than -60.
- (let ((hour-fix
- (if (< minute 0)
- ;;(/ (- minute 59) 60) (/ minute 60)
- ;; ANSI C compliance about truncation of integer division
- ;; by eggert@twinsun.com (Paul Eggert)
- (- (/ (- 59 minute) 60)) (/ minute 60))))
+(defun timezone-fix-time (date local timezone)
+ "Convert DATE (default timezone LOCAL) to YYYY-MM-DD-HH-MM-SS-ZONE vector.
+If LOCAL is nil, it is assumed to be GMT.
+If TIMEZONE is nil, use the local time zone."
+ (let* ((date (timezone-parse-date date))
+ (year (string-to-number (aref date 0)))
+ (year (cond ((< year 69)
+ (+ year 2000))
+ ((< year 100)
+ (+ year 1900))
+ ((< year 1000) ; possible 3-digit years.
+ (+ year 1900))
+ (t year)))
+ (month (string-to-number (aref date 1)))
+ (day (string-to-number (aref date 2)))
+ (time (timezone-parse-time (aref date 3)))
+ (hour (string-to-number (aref time 0)))
+ (minute (string-to-number (aref time 1)))
+ (second (string-to-number (aref time 2)))
+ (local (or (aref date 4) local)) ;Use original if defined
+ (timezone
+ (or timezone
+ (timezone-time-zone-from-absolute
+ (timezone-absolute-from-gregorian month day year)
+ (+ second (* 60 (+ minute (* 60 hour)))))))
+ (diff (- (timezone-zone-to-minute timezone)
+ (timezone-zone-to-minute local)))
+ (minute (+ minute diff))
+ (hour-fix (floor minute 60)))
(setq hour (+ hour hour-fix))
- (setq minute (- minute (* 60 hour-fix))))
- ;; HOUR may be larger than 24 or smaller than 0.
- (cond ((<= 24 hour) ;24 -> 00
- (setq hour (- hour 24))
- (setq day (1+ day))
- (if (< (timezone-last-day-of-month month year) day)
- (progn
- (setq month (1+ month))
- (setq day 1)
- (if (< 12 month)
- (progn
- (setq month 1)
- (setq year (1+ year))
- ))
- )))
- ((> 0 hour)
- (setq hour (+ hour 24))
- (setq day (1- day))
- (if (> 1 day)
- (progn
- (setq month (1- month))
- (if (> 1 month)
- (progn
- (setq month 12)
- (setq year (1- year))
- ))
- (setq day (timezone-last-day-of-month month year))
- )))
- )
- (vector year month day hour minute second))
+ (setq minute (- minute (* 60 hour-fix)))
+ ;; HOUR may be larger than 24 or smaller than 0.
+ (cond ((<= 24 hour) ;24 -> 00
+ (setq hour (- hour 24))
+ (setq day (1+ day))
+ (when (< (timezone-last-day-of-month month year) day)
+ (setq month (1+ month))
+ (setq day 1)
+ (when (< 12 month)
+ (setq month 1)
+ (setq year (1+ year)))))
+ ((> 0 hour)
+ (setq hour (+ hour 24))
+ (setq day (1- day))
+ (when (> 1 day)
+ (setq month (1- month))
+ (when (> 1 month)
+ (setq month 12)
+ (setq year (1- year)))
+ (setq day (timezone-last-day-of-month month year)))))
+ (vector year month day hour minute second timezone)))
;; Partly copied from Calendar program by Edward M. Reingold.
;; Thanks a lot.
(not (zerop (% year 100))))
(zerop (% year 400))))
+(defun timezone-day-number (month day year)
+ "Return the day number within the year of the date month/day/year."
+ (let ((day-of-year (+ day (* 31 (1- month)))))
+ (if (> month 2)
+ (progn
+ (setq day-of-year (- day-of-year (/ (+ 23 (* 4 month)) 10)))
+ (if (timezone-leap-year-p year)
+ (setq day-of-year (1+ day-of-year)))))
+ day-of-year))
+
+(defun timezone-absolute-from-gregorian (month day year)
+ "The number of days between the Gregorian date 12/31/1 BC and month/day/year.
+The Gregorian date Sunday, December 31, 1 BC is imaginary."
+ (+ (timezone-day-number month day year);; Days this year
+ (* 365 (1- year));; + Days in prior years
+ (/ (1- year) 4);; + Julian leap years
+ (- (/ (1- year) 100));; - century years
+ (/ (1- year) 400)));; + Gregorian leap years
+
+(provide 'timezone)
+
+;;; arch-tag: e23d5bc6-f32d-48ba-8996-323e9d654b3f
;;; timezone.el ends here