(defun sd-adjust-time-transcriber (dif)
  "adds DIFference to every time-mark in transcriber-files"
  (interactive
   "NDifference number: ")
  (setq sd-time-regexp "[tT]ime=\"\\([1-90.]+\\)\"")
  (while (search-forward-regexp sd-time-regexp nil t)
    (if (not (= (string-to-number (match-string 1)) 0))
	(replace-match (format "%.3f" 
			       (+ (string-to-number 
				   (match-string 1)) dif)) 
		       nil nil nil 1))))

(defun sd-adjust-time-shoebox (dif)
  "adds DIFference to every time-mark"
  (interactive
   "NDifference number: ")
  (setq sd-time-regexp "^\\\\ref.* \\([1-90.]+\\)$")
  (while  (search-forward-regexp sd-time-regexp nil t)
    (if (not (= (string-to-number (match-string 1)) 0))
	(replace-match (format "%08.3f" 
			       (+ (string-to-number 
				   (match-string 1)) dif))
		       nil nil nil 1))))