;;; timezone.el --- time zone package for GNU Emacs ;; Copyright (C) 1990, 1991, 1992, 1993, 1996, 1999 Free Software Foundation, Inc. ;; Author: Masanobu Umeda ;; Maintainer: umerin@mse.kyutech.ac.jp ;; Keywords: news ;; 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; 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, Inc., 59 Temple Place - Suite 330, ;; Boston, MA 02111-1307, USA. ;;; Commentary: ;;; Code: (defvar timezone-world-timezones '(("PST" . -800) ("PDT" . -700) ("MST" . -700) ("MDT" . -600) ("CST" . -600) ("CDT" . -500) ("EST" . -500) ("EDT" . -400) ("AST" . -400) ;by ("NST" . -330) ;by ("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))) )) ;; ;; 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]. 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) (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) (day 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 "\\([^ \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 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)) ) (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-int 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 (and year month) (vector year month day time zone) (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 minute second) (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 (match-string hour time) "0") (if minute (match-string minute time) "0") (if second (match-string second time) "0")))) ;; 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 (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 (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)) (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 (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 69) (+ year 2000)) ((< year 100) (+ year 1900)) ((< year 1000) ; possible 3-digit years. (+ 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 (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)) (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. (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) "Returns 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 (provide 'timezone) ;;; arch-tag: e23d5bc6-f32d-48ba-8996-323e9d654b3f ;;; timezone.el ends here