(format-time-string): Support the construct `%z'.

[elisp/apel.git] / poe.el

diff --git a/poe.el b/poe.el
index 5224803..d2a9309 100644 (file)
--- a/poe.el
+++ b/poe.el
@@ -1418,6 +1418,11 @@ Not fully compatible especially when invalid format is specified."
                 ((eq cur-char ?Z)
                  (setq change-case (not change-case))
                  (downcase (cadr (current-time-zone))))
+                ((eq cur-char ?z)
+                 (let ((tz (car (current-time-zone))))
+                   (if (< tz 0)
+                       (format "-%02d%02d" (/ (- tz) 3600) (/ (% (- tz) 3600) 60))
+                     (format "+%02d%02d" (/ tz 3600) (/ (% tz 3600) 60)))))
                 (t
                  (concat
                   "%"
@@ -1459,6 +1464,24 @@ Not fully compatible especially when invalid format is specified."
   (setq current-load-list (cons 'format-time-string current-load-list))
   (put 'format-time-string 'defun-maybe t))))
 
+;; Emacs 19.29-19.34/XEmacs: format-time-string() doesn't support `%z'.
+(unless (string-match "\\`[\\-\\+][0-9]+\\'"
+                     (format-time-string "%z" (current-time)))
+  (defadvice format-time-string
+    (before support-timezone-in-numeric-form activate compile)
+    "Advice to support the construct `%z'."
+    (if (let ((case-fold-search nil))
+         (string-match "\\(\\(\\`\\|[^%]\\)\\(%%\\)*\\)%z" (ad-get-arg 0)))
+       (ad-set-arg
+        0
+        (concat
+         (substring (ad-get-arg 0) 0 (match-end 1))
+         (let ((tz (car (current-time-zone))))
+           (if (< tz 0)
+               (format "-%02d%02d" (/ (- tz) 3600) (/ (% (- tz) 3600) 60))
+             (format "+%02d%02d" (/ tz 3600) (/ (% tz 3600) 60))))
+         (substring (ad-get-arg 0) (match-end 0)))))))
+
 ;; Emacs 20.1/XEmacs 20.3(?) and later: (split-string STRING &optional PATTERN)
 ;; Here is a XEmacs version.
 (defun-maybe split-string (string &optional pattern)