X-Git-Url: http://git.chise.org/gitweb/?a=blobdiff_plain;f=lisp%2Ftime-date.el;h=9598f7d46f36d11e9e775df3e68712dea15c21b4;hb=05e1ead695394f7d9fae8730e90e8db6dce2cc17;hp=c40ddbead30f91b8ed78325bf907f2bc3416045d;hpb=8944908a9e5aa4e0e29843510245e84337a2a8a5;p=elisp%2Fgnus.git- diff --git a/lisp/time-date.el b/lisp/time-date.el index c40ddbe..9598f7d 100644 --- a/lisp/time-date.el +++ b/lisp/time-date.el @@ -1,8 +1,10 @@ ;;; time-date.el --- Date and time handling functions -;; Copyright (C) 1998,99 Free Software Foundation, Inc. +;; Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc. ;; Author: Lars Magne Ingebrigtsen ;; Masanobu Umeda +;; Keywords: mail news util + ;; This file is part of GNU Emacs. ;; GNU Emacs is free software; you can redistribute it and/or modify @@ -24,34 +26,51 @@ ;;; Code: +(eval-when-compile (require 'cl)) + (require 'parse-time) +(autoload 'timezone-make-date-arpa-standard "timezone") + +;;;###autoload (defun date-to-time (date) - "Convert DATE into time." + "Parse a string that represents a date-time and return a time value." (condition-case () - (apply 'encode-time (parse-time-string date)) + (apply 'encode-time + (parse-time-string + ;; `parse-time-string' isn't sufficiently general or + ;; robust. It fails to grok some of the formats that + ;; timzeone does (e.g. dodgy post-2000 stuff from some + ;; Elms) and either fails or returns bogus values. Lars + ;; reverted this change, but that loses non-trivially + ;; often for me. -- fx + (timezone-make-date-arpa-standard date))) (error (error "Invalid date: %s" date)))) (defun time-to-seconds (time) - "Convert TIME to a floating point number." + "Convert time value TIME to a floating point number. +You can use `float-time' instead." (+ (* (car time) 65536.0) (cadr time) - (/ (or (caddr time) 0) 1000000.0))) + (/ (or (nth 2 time) 0) 1000000.0))) +;;;###autoload (defun seconds-to-time (seconds) - "Convert SECONDS (a floating point number) to an Emacs time structure." + "Convert SECONDS (a floating point number) to a time value." (list (floor seconds 65536) (floor (mod seconds 65536)) (floor (* (- seconds (ffloor seconds)) 1000000)))) +;;;###autoload (defun time-less-p (t1 t2) - "Say whether time T1 is less than time T2." + "Say whether time value T1 is less than time value T2." (or (< (car t1) (car t2)) (and (= (car t1) (car t2)) (< (nth 1 t1) (nth 1 t2))))) +;;;###autoload (defun days-to-time (days) - "Convert DAYS into time." + "Convert DAYS into a time value." (let* ((seconds (* 1.0 days 60 60 24)) (rest (expt 2 16)) (ms (condition-case nil (floor (/ seconds rest)) @@ -59,8 +78,10 @@ (list ms (condition-case nil (round (- seconds (* ms rest))) (range-error (expt 2 16)))))) +;;;###autoload (defun time-since (time) - "Return the time since TIME, which is either an internal time or a date." + "Return the time elapsed since TIME. +TIME should be either a time value or a date-time string." (when (stringp time) ;; Convert date strings to internal time. (setq time (date-to-time time))) @@ -70,26 +91,65 @@ (list (- (+ (car current) (if rest -1 0)) (car time)) (- (+ (or rest 0) (nth 1 current)) (nth 1 time))))) -(defun subtract-time (t1 t2) - "Subtract two internal times." +;;;###autoload +(defalias 'subtract-time 'time-subtract) + +;;;###autoload +(defun time-subtract (t1 t2) + "Subtract two time values. +Return the difference in the format of a time value." (let ((borrow (< (cadr t1) (cadr t2)))) (list (- (car t1) (car t2) (if borrow 1 0)) (- (+ (if borrow 65536 0) (cadr t1)) (cadr t2))))) +;;;###autoload +(defun time-add (t1 t2) + "Add two time values. One should represent a time difference." + (let ((high (car t1)) + (low (if (consp (cdr t1)) (nth 1 t1) (cdr t1))) + (micro (if (numberp (car-safe (cdr-safe (cdr t1)))) + (nth 2 t1) + 0)) + (high2 (car t2)) + (low2 (if (consp (cdr t2)) (nth 1 t2) (cdr t2))) + (micro2 (if (numberp (car-safe (cdr-safe (cdr t2)))) + (nth 2 t2) + 0))) + ;; Add + (setq micro (+ micro micro2)) + (setq low (+ low low2)) + (setq high (+ high high2)) + + ;; Normalize + ;; `/' rounds towards zero while `mod' returns a positive number, + ;; so we can't rely on (= a (+ (* 100 (/ a 100)) (mod a 100))). + (setq low (+ low (/ micro 1000000) (if (< micro 0) -1 0))) + (setq micro (mod micro 1000000)) + (setq high (+ high (/ low 65536) (if (< low 0) -1 0))) + (setq low (logand low 65535)) + + (list high low micro))) + +;;;###autoload (defun date-to-day (date) - "Return the number of days between year 1 and DATE." + "Return the number of days between year 1 and DATE. +DATE should be a date-time string." (time-to-days (date-to-time date))) +;;;###autoload (defun days-between (date1 date2) - "Return the number of days between DATE1 and DATE2." + "Return the number of days between DATE1 and DATE2. +DATE1 and DATE2 should be date-time strings." (- (date-to-day date1) (date-to-day date2))) +;;;###autoload (defun date-leap-year-p (year) "Return t if YEAR is a leap year." (or (and (zerop (% year 4)) (not (zerop (% year 100)))) (zerop (% year 400)))) +;;;###autoload (defun time-to-day-in-year (time) "Return the day number within the year of the date month/day/year." (let* ((tim (decode-time time)) @@ -103,22 +163,30 @@ (setq day-of-year (1+ day-of-year)))) day-of-year)) +;;;###autoload (defun time-to-days (time) "The number of days between the Gregorian date 0001-12-31bce and TIME. +TIME should be a time value. The Gregorian date Sunday, December 31, 1bce is imaginary." (let* ((tim (decode-time time)) (month (nth 4 tim)) (day (nth 3 tim)) (year (nth 5 tim))) - (+ (time-to-day-in-year time) ; Days this year + (+ (time-to-day-in-year time) ; 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 time-to-number-of-days (time) + "Return the number of days represented by TIME. +The number of days will be returned as a floating point number." + (/ (+ (* 1.0 65536 (car time)) (cadr time)) (* 60 60 24))) + +;;;###autoload (defun safe-date-to-time (date) - "Parse DATE and return a time structure. -If DATE is malformed, a zero time will be returned." + "Parse a string that represents a date-time and return a time value. +If DATE is malformed, return a time value of zeros." (condition-case () (date-to-time date) (error '(0 0))))