Commit facb137b authored by Jim Blandy's avatar Jim Blandy
Browse files

Some time-handling patches from Paul Eggert:

	* calendar.el (calendar-current-time-zone): New function.
	(calendar-time-zone, calendar-standard-time-zone-name,
	calendar-daylight-time-zone-name): Use it instead of current-time-zone.
	* sendmail.el (mail-do-fcc): Use the same absolute time for both
	current-time-string and current-time-zone.  Adjust to new format
	returned by current-time-zone.
parent d52c5f58
......@@ -479,6 +479,55 @@ For example, -74.0 for New York City.")
`calendar-longitude', calendar-latitude'. Default value is just the latitude,
longitude pair.")
(defun calendar-current-time-zone ()
"Return the offset, savings state, and names for the current time zone.
This returns a list of the form (OFFSET SAVINGS-FLAG STANDARD SAVINGS).
This list is calculated from a heuristic that is usually correct;
to get more reliable results, use current-time-zone.
OFFSET is an integer specifying how many minutes east of Greenwich the
current time zone is located. A negative value means west of
Greenwich. This describes the standard time; if daylight
savings time is in effect, it does not affect this value.
SAVINGS-FLAG is non-nil iff daylight savings time or some other sort
of seasonal time adjustment is in effect.
STANDARD is a string giving the name of the time zone when no seasonal
time adjustment is in effect.
SAVINGS is a string giving the name of the time zone when there is a
seasonal time adjustment in effect.
If the local area does not use a seasonal time adjustment,
SAVINGS-FLAG is always nil, and STANDARD and SAVINGS are equal.
Some operating systems cannot provide all this information to Emacs;
in this case, calendar-current-time-zone returns a list containing nil for
the data it can't find."
(let* ((quarter-year-seconds 7889238.0) ; # number of seconds in 1/4 year
(current-time-arithmetic-base 65536.0)
(now (current-time))
(now-zone (current-time-zone now))
(now-offset (car now-zone))
(now-name (car (cdr now-zone)))
(probe-offset now-offset)
(i 0))
;; Heuristic: probe the time zone offset in the next three calendar
;; quarters, looking for a time zone offset different from now.
(while (and (< i 4) (eq now-offset probe-offset))
(let ((probe
(list (+ (car now) (round (/ (* i quarter-year-seconds)
0 0)))
(setq probe-zone (current-time-zone probe))
(setq probe-offset (car probe-zone))
(setq i (1+ i))))
(if (or (eq now-offset probe-offset) (not now-offset) (not probe-offset))
(list (and now-offset (/ now-offset 60)) nil now-name now-name)
(let ((std-offset (min now-offset probe-offset))
(probe-name (car (cdr probe-zone))))
(list (/ std-offset 60)
(if (eq std-offset now-offset) now-name probe-name)
(if (eq std-offset now-offset) probe-name now-name))))))
;;; Since the following three defvars are marked to go into
;;; loaddefs.el, they will be evaluated when Emacs is dumped.
;;; However, these variables' appropriate values really depend on the
......@@ -497,7 +546,7 @@ If this is nil, it will be set to the local time zone when the calendar
package loads.")
;;; If the user has given this a real value, don't wipe it out.
(or calendar-time-zone
(setq calendar-time-zone (car (current-time-zone))))
(setq calendar-time-zone (car (calendar-current-time-zone))))
(defvar calendar-standard-time-zone-name nil
......@@ -509,7 +558,7 @@ package loads.")
;;; If the user has given this a value, don't wipe it out.
(or calendar-standard-time-zone-name
(setq calendar-standard-time-zone-name
(car (nthcdr 2 (current-time-zone)))))
(car (nthcdr 2 (calendar-current-time-zone)))))
(defvar calendar-daylight-time-zone-name nil
......@@ -521,7 +570,7 @@ package loads.")
;;; If the user has given this a value, don't wipe it out.
(or calendar-daylight-time-zone-name
(setq calendar-daylight-time-zone-name
(car (nthcdr 3 (current-time-zone)))))
(car (nthcdr 3 (calendar-current-time-zone)))))
(defvar calendar-daylight-savings-starts
......@@ -355,6 +355,7 @@ the user from the mailer."
(defun mail-do-fcc (header-end)
(let (fcc-list
(rmailbuf (current-buffer))
(time (current-time))
(tembuf (generate-new-buffer " rmail output"))
(case-fold-search t))
......@@ -369,8 +370,8 @@ the user from the mailer."
(delete-region (match-beginning 0)
(progn (forward-line 1) (point))))
(let* ((foo (current-time-zone))
(offset (+ (car foo) (if (nth 1 foo) 60 0)))
(let* ((foo (current-time-zone time))
(offset (if (car foo) (/ (car foo) 60) 0))
(abs (abs offset)))
(setq timezone (format "%s%02d%02d"
(if (< offset 0) "-" "+")
......@@ -379,7 +380,7 @@ the user from the mailer."
(set-buffer tembuf)
(insert "From " (user-login-name) " "
(current-time-string) "\n")
(current-time-string time) "\n")
;; Insert the time zone before the year.
(forward-char -1)
(forward-word -1)
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