Change to ISO 8601 date formats, without time of day.

(change-log-font-lock-keywords): Adjust accordingly.
(add-change-log-entry): Compare and insert with new date format.
(change-log-mode): Make `paragraph-start' and `paragraph-separate' use \<
like `page-delimiter' for consistency.
(change-log-time-zone-rule): New variable.
(iso8601-time-zone): New function.
(add-change-log-entry): If change-log-time-zone-rule is non-nil, calculate
date according to that rule, and indicate resulting time zone.

diff --git a/lisp/add-log.el b/lisp/add-log.el
index ff1ecabbdcc2b2544f122c779eccc09ecc5648da..cf4e46d033a1c22b07899e6ad37d02355823b743 100644 (file)
--- a/lisp/add-log.el
+++ b/lisp/add-log.el
@@ -47,7 +47,7 @@ This defaults to the value returned by the `user-full-name' function.")
 This defaults to the value of `user-mail-address'.")
 
 (defvar change-log-font-lock-keywords
-  '(("^[SMTWF].+" . font-lock-function-name-face)      ; Date line.
+  '(("^[12].+" . font-lock-function-name-face) ; Date line.
     ("^\t\\* \\([^ :\n]+\\)" 1 font-lock-comment-face) ; File name.
     ("(\\([^)\n]+\\)):" 1 font-lock-keyword-face))     ; Function name.
   "Additional expressions to highlight in Change Log mode.")
@@ -58,6 +58,24 @@ This defaults to the value of `user-mail-address'.")
     nil
   (setq change-log-mode-map (make-sparse-keymap)))
 
+(defvar change-log-time-zone-rule nil
+  "Time zone used for calculating change log time stamps.
+It takes the same format as the TZ argument of `set-time-zone-rule'.
+If nil, use local time.")
+
+(defun iso8601-time-zone (time)
+  (let* ((utc-offset (or (car (current-time-zone time)) 0))
+        (sign (if (< utc-offset 0) ?- ?+))
+        (sec (abs utc-offset))
+        (ss (% sec 60))
+        (min (/ sec 60))
+        (mm (% min 60))
+        (hh (/ min 60)))
+    (format (cond ((not (zerop ss)) "%c%02d:%02d:%02d")
+                 ((not (zerop mm)) "%c%02d:%02d")
+                 (t "%c%02d"))
+           sign hh mm ss)))
+
 (defun change-log-name ()
   (or change-log-default-name
       (if (eq system-type 'vax-vms) 
@@ -148,7 +166,8 @@ Optional arg (interactive prefix) non-nil means prompt for user name and site.
 Second arg is file name of change log.  If nil, uses `change-log-default-name'.
 Third arg OTHER-WINDOW non-nil means visit in other window.
 Fourth arg NEW-ENTRY non-nil means always create a new entry at the front;
-never append to an existing entry."
+never append to an existing entry.  Today's date is calculated according to
+`change-log-time-zone-rule' if non-nil, otherwise in local time."
   (interactive (list current-prefix-arg
                     (prompt-for-change-log-name)))
   (or add-log-full-name
@@ -188,14 +207,23 @@ never append to an existing entry."
        (change-log-mode))
     (undo-boundary)
     (goto-char (point-min))
-    (if (looking-at (concat (regexp-quote (substring (current-time-string)
-                                                    0 10))
-                           ".* " (regexp-quote add-log-full-name)
-                           "  <" (regexp-quote add-log-mailing-address)))
-       (forward-line 1)
-      (insert (current-time-string)
-             "  " add-log-full-name
-             "  <" add-log-mailing-address ">\n\n"))
+    (let ((new-entry (concat (if change-log-time-zone-rule
+                                (let ((tz (getenv "TZ"))
+                                      (now (current-time)))
+                                  (unwind-protect
+                                      (progn
+                                        (set-time-zone-rule
+                                         change-log-time-zone-rule)
+                                        (concat 
+                                         (format-time-string "%Y-%m-%d " now)
+                                         (iso8601-time-zone now)))
+                                    (set-time-zone-rule tz)))
+                              (format-time-string "%Y-%m-%d"))
+                            "  " add-log-full-name
+                            "  <" add-log-mailing-address ">")))
+      (if (looking-at (regexp-quote new-entry))
+         (forward-line 1)
+       (insert new-entry "\n\n")))
 
     ;; Search only within the first paragraph.
     (if (looking-at "\n*[^\n* \t]")
@@ -290,8 +318,8 @@ Runs `change-log-mode-hook'."
   ;; Let each entry behave as one paragraph:
   ;; We really do want "^" in paragraph-start below: it is only the lines that
   ;; begin at column 0 (despite the left-margin of 8) that we are looking for.
-  (set (make-local-variable 'paragraph-start) "\\s *$\\|\f\\|^\\sw")
-  (set (make-local-variable 'paragraph-separate) "\\s *$\\|\f\\|^\\sw")
+  (set (make-local-variable 'paragraph-start) "\\s *$\\|\f\\|^\\<")
+  (set (make-local-variable 'paragraph-separate) "\\s *$\\|\f\\|^\\<")
   ;; Let all entries for one day behave as one page.
   ;; Match null string on the date-line so that the date-line
   ;; is grouped with what follows.