Emacs lisp for semi-automatic update of "CreationDate" comment on a postscript file

ps-mode.el

(defun format-time-string-with-locale-c (fmt)
  (let ((system-time-locale "C")) (format-time-string fmt)))

(require 'ps-mode)
(defun ps-mode-update-creationdate ()
  (interactive nil)
  (save-excursion
	(goto-char (point-min))
	(and
	 (re-search-forward "^%%CreationDate: " nil t)
	 (y-or-n-p "Update really?")
	 (and
	  (re-search-forward ".*$" nil t)
	  (let ((tstr (format-time-string-with-locale-c "%c")))
		(replace-match tstr))))
	)
  )

(define-key ps-mode-map "\C-c\C-d" 'ps-mode-update-creationdate)