+;;; timezone.el --- time zone package for GNU Emacs
+
+;; Copyright (C) 1990, 1991, 1992, 1993 Free Software Foundation, Inc.
+
+;; Author: Masanobu Umeda
+;; Maintainer: umerin@mse.kyutech.ac.jp
+;; Keywords: news
+
+;; This file 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.
+
+;; This file is distributed in the hope that it will be useful,
+;; 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.
+
+;; 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.
+
+;;; Commentary:
+
+;; Modified 1 February 1994 by Kyle Jones to fix broken
+;; timezone-floor function.
+
+;; Modified 25 January 1994 by Kyle Jones so that it will
+;; work under version 18 of Emacs. Provided timezone-floor
+;; and timezone-abs functions.
+
+;; Modified 4 October 1999 by Yuuichi Teranishi so that it will
+;; work with old GNUS 3.14.4 under version 18 of Emacs.
+
+;; Modified 5 October 1999 by Yuuichi Teranishi to fix y2k problem
+;; of timezone-parse-date function.
+
+;;; Code:
+
+(defvar timezone-world-timezones
+ '(("PST" . -800)
+ ("PDT" . -700)
+ ("MST" . -700)
+ ("MDT" . -600)
+ ("CST" . -600)
+ ("CDT" . -500)
+ ("EST" . -500)
+ ("EDT" . -400)
+ ("AST" . -400) ;by <clamen@CS.CMU.EDU>
+ ("NST" . -330) ;by <clamen@CS.CMU.EDU>
+ ("UT" . +000)
+ ("GMT" . +000)
+ ("BST" . +100)
+ ("MET" . +100)
+ ("EET" . +200)
+ ("JST" . +900)
+ ("GMT+1" . +100) ("GMT+2" . +200) ("GMT+3" . +300)
+ ("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) ("GMT+13" . +1300)
+ ("GMT-1" . -100) ("GMT-2" . -200) ("GMT-3" . -300)
+ ("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 +-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)
+ ("APR" . 4)("MAY" . 5)("JUN" . 6)
+ ("JUL" . 7)("AUG" . 8)("SEP" . 9)
+ ("OCT" . 10)("NOV" . 11)("DEC" . 12))
+ "Alist of first three letters of a month and its numerical representation.")
+
+(defun timezone-make-date-arpa-standard (date &optional local timezone)
+ "Convert DATE to an arpanet standard date.
+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))
+ (aref new 6))
+ ))
+
+(defun timezone-make-date-sortable (date &optional local timezone)
+ "Convert DATE to a sortable date string.
+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)))
+ ))
+
+\f
+;;
+;; Parsers and Constructors of Date and Time
+;;
+
+(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."
+ (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 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.
+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)
+ (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]"
+ (condition-case nil
+ (progn
+ ;; 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)
+ (day nil)
+ (time nil)
+ (zone nil)) ;This may be nil.
+ (cond ((string-match
+ "\\([^ \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
+ "\\([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))
+ ((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 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]+" date)
+ ;; Styles: (5) without timezone.
+ (setq year 3 month 2 day 1 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)
+ ;; 2 digit years are bogus, so guess the century
+ (let ((yr (string-to-int year)))
+ (when (>= yr 100)
+ ;; What does a three digit year mean?
+ (setq yr (- yr 100)))
+ (setq year (format "%d%02d"
+ (if (< yr 70)
+ 20
+ 19)
+ yr))))
+ (let ((string (substring date
+ (match-beginning month)
+ (+ (match-beginning month) 3))))
+ (setq month
+ (int-to-string
+ (cdr (assoc (upcase string) 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))))
+ ;; Return a vector.
+ (if year
+ (vector year month day time zone)
+ (vector "0" "0" "0" "0" nil))
+ )
+ )
+ (t (signal 'error (list "Invalid date string" date)))))
+
+(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))
+ (cond ((string-match "\\`\\([0-9]+\\):\\([0-9]+\\):\\([0-9]+\\)\\'" time)
+ ;; HH:MM:SS
+ (setq hour 1 minute 2 second 3))
+ ((string-match "\\`\\([0-9]+\\):\\([0-9]+\\)\\'" time)
+ ;; HH:MM
+ (setq hour 1 minute 2 second nil))
+ ((string-match "\\`\\([0-9][0-9]\\)\\([0-9][0-9]\\)\\([0-9][0-9]\\)\\'" time)
+ ;; HHMMSS
+ (setq hour 1 minute 2 second 3))
+ ((string-match "\\`\\([0-9][0-9]\\)\\([0-9][0-9]\\)\\'" time)
+ ;; HHMM
+ (setq hour 1 minute 2 second nil))
+ )
+ ;; 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"))
+ ))
+
+\f
+;; Miscellaneous
+
+(defun timezone-zone-to-minute (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 (and (stringp timezone) (cdr (assoc (upcase timezone) timezone-world-timezones)))
+ ;; +900
+ timezone))
+ (if (stringp timezone)
+ (setq timezone (string-to-int timezone)))
+ ;; Taking account of minute in timezone.
+ ;; HHMM -> MM
+ (let* ((abszone (timezone-abs timezone))
+ (minutes (+ (* 60 (/ abszone 100)) (% abszone 100))))
+ (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))
+ (days-1 (/ days 65536))
+ (days-2 (mod (/ days 256) 256))
+ (days-3 (mod days 256))
+ ;; (seconds-per-day (float 86400))
+ (seconds-per-day-1 1)
+ (seconds-per-day-2 81)
+ (seconds-per-day-3 128)
+ ;; (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)))
+ (seconds-1 (/ seconds 65536))
+ (seconds-2 (mod (/ seconds 256) 256))
+ (seconds-3 (mod seconds 256))
+ hi lo
+ r
+ seconds-per-day*days-1
+ seconds-per-day*days-2
+ seconds-per-day*days-3)
+ (setq r (* days-3 seconds-per-day-3)
+ seconds-per-day*days-3 (mod r 256))
+ (setq r (+ (/ r 256)
+ (* days-2 seconds-per-day-3)
+ (* days-3 seconds-per-day-2))
+ seconds-per-day*days-2 (mod r 256))
+ (setq seconds-per-day*days-1 (+ (/ r 256)
+ (* days-1 seconds-per-day-3)
+ (* (/ days 256) seconds-per-day-2)
+ (* days seconds-per-day-1)))
+ (setq r (+ seconds-2 seconds-per-day*days-2)
+ seconds-2 (mod r 256)
+ seconds-1 (+ seconds-1 (/ r 256)))
+ (setq lo (+ (* seconds-2 256)
+ seconds-3 seconds-per-day*days-3))
+ (setq hi (+ seconds-1 seconds-per-day*days-1))
+ ;; (and (< (abs (- seconds (+ hibase lo))) 2) ; Check for integer overflow.
+ ;; (cons hi lo))
+ (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))))))
+
+(defsubst timezone-fix-time-1 (year month day hour minute second)
+ "Fix date and time.
+For old `timezone-fix-time' function.
+Arguments are YEAR, MONTH, DAY, HOUR, MINUTE and SECOND."
+ ;; 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))))
+ (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))
+
+(defsubst timezone-fix-time-2 (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-int (aref date 0)))
+ (year (cond ((< year 50)
+ (+ year 2000))
+ ((< year 100)
+ (+ year 1900))
+ (t year)))
+ (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
+ (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 (timezone-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 timezone)))
+
+(defun timezone-fix-time (a1 a2 a3 &optional a4 a5 a6)
+ "Fix date and time.
+(Old API: A1=YEAR A2=MONTH A3=DAY A4=HOUR A5=MINUTE A6=SECOND).
+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.
+(New API: A1=DATE A2=LOCAL A3=TIMEZONE)"
+ (if a4
+ (timezone-fix-time-1 a1 a2 a3 a4 a5 a6)
+ (timezone-fix-time-2 a1 a2 a3)))
+
+;; Partly copied from Calendar program by Edward M. Reingold.
+;; Thanks a lot.
+
+(defun timezone-last-day-of-month (month year)
+ "The last day in MONTH during YEAR."
+ (if (and (= month 2) (timezone-leap-year-p year))
+ 29
+ (aref [31 28 31 30 31 30 31 31 30 31 30 31] (1- month))))
+
+(defun timezone-leap-year-p (year)
+ "Return t if YEAR is a Gregorian leap year."
+ (or (and (zerop (% year 4))
+ (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
+
+(defun timezone-abs (n)
+ "Return the absolute value of N."
+ (if (fboundp 'abs)
+ (abs n)
+ (if (< n 0) (- n) n)))
+
+(defun timezone-floor (n &optional divisor)
+ "Return the largest integer no grater than N.
+With optional DIVISOR, return the largest integer no greater than ARG/DIVISOR."
+ (if (fboundp 'floor)
+ (floor n divisor)
+ (if (null divisor)
+ (setq divisor 1))
+ (if (< n 0)
+ (- (/ (- divisor 1 n) divisor))
+ (/ n divisor))))
+
+(product-provide (provide 'timezone) (require 'apel-ver))
+
+;;; timezone.el ends here