diff --git a/lisp/org.el b/lisp/org.el
index 6651436eb..770f84c84 100644
--- a/lisp/org.el
+++ b/lisp/org.el
@@ -13332,77 +13332,81 @@ This function is run automatically after each state change to a DONE state."
 			     org-log-repeat)))
       (org-back-to-heading t)
       (org-add-planning-info nil nil 'closed)
-      (let ((end (save-excursion (outline-next-heading) (point))))
+      (let ((end (save-excursion (outline-next-heading) (point)))
+	    (planning-re (regexp-opt
+			  (list org-scheduled-string org-deadline-string))))
 	(while (re-search-forward org-ts-regexp end t)
-	  (when (save-match-data
-		  (or (org-at-planning-p)
-		      (org-at-property-p)
-		      (eq (org-element-type (save-excursion
-					      (backward-char)
-					      (org-element-context)))
-			  'timestamp)))
-	    (let ((type (cond ((match-end 1) org-scheduled-string)
-			      ((match-end 3) org-deadline-string)
-			      (t "Plain:")))
-		  (ts (or (match-string 2) (match-string 4) (match-string 0))))
-	      (cond
-	       ((not
-		 (string-match "\\([.+]\\)?\\(\\+[0-9]+\\)\\([hdwmy]\\)" ts))
-		;; Time-stamps without a repeater are usually skipped.
-		;; However, a SCHEDULED time-stamp without one is
-		;; removed, as it is considered as no longer relevant.
-		(when (equal type org-scheduled-string)
-		  (org-remove-timestamp-with-keyword type)))
-	       (t
-		(let ((n (string-to-number (match-string 2 ts)))
-		      (what (match-string 3 ts)))
-		  (when (equal what "w") (setq n (* n 7) what "d"))
-		  (when (and (equal what "h")
-			     (not (string-match-p "[0-9]\\{1,2\\}:[0-9]\\{2\\}"
-						  ts)))
-		    (user-error
-		     "Cannot repeat in Repeat in %d hour(s) because no hour \
+	  (let* ((ts (match-string 0))
+		 (planning? (org-at-planning-p))
+		 (type (if (not planning?) "Plain:"
+			 (save-excursion
+			   (re-search-backward
+			    planning-re (line-beginning-position) t)
+			   (match-string 0)))))
+	    (cond
+	     ;; Ignore fake time-stamps (e.g., within comments).
+	     ((and (not planning?)
+		   (not (org-at-property-p))
+		   (not (eq 'timestamp
+			    (org-element-type (save-excursion
+						(backward-char)
+						(org-element-context)))))))
+	     ;; Time-stamps without a repeater are usually skipped.
+	     ;; However, a SCHEDULED time-stamp without one is
+	     ;; removed, as it is considered as no longer relevant.
+	     ((not (string-match "\\([.+]\\)?\\(\\+[0-9]+\\)\\([hdwmy]\\)" ts))
+	      (when (equal type org-scheduled-string)
+		(org-remove-timestamp-with-keyword type)))
+	     (t
+	      (let ((n (string-to-number (match-string 2 ts)))
+		    (what (match-string 3 ts)))
+		(when (equal what "w") (setq n (* n 7) what "d"))
+		(when (and (equal what "h")
+			   (not (string-match-p "[0-9]\\{1,2\\}:[0-9]\\{2\\}"
+						ts)))
+		  (user-error
+		   "Cannot repeat in Repeat in %d hour(s) because no hour \
 has been set"
-		     n))
-		  ;; Preparation, see if we need to modify the start
-		  ;; date for the change.
-		  (when (match-end 1)
-		    (let ((time (save-match-data (org-time-string-to-time ts))))
-		      (cond
-		       ((equal (match-string 1 ts) ".")
-			;; Shift starting date to today
-			(org-timestamp-change
-			 (- (org-today) (time-to-days time))
-			 'day))
-		       ((equal (match-string 1 ts) "+")
-			(let ((nshiftmax 10)
-			      (nshift 0))
-			  (while (or (= nshift 0)
-				     (not (time-less-p (current-time) time)))
-			    (when (= (cl-incf nshift) nshiftmax)
-			      (or (y-or-n-p
-				   (format "%d repeater intervals were not \
+		   n))
+		;; Preparation, see if we need to modify the start
+		;; date for the change.
+		(when (match-end 1)
+		  (let ((time (save-match-data (org-time-string-to-time ts))))
+		    (cond
+		     ((equal (match-string 1 ts) ".")
+		      ;; Shift starting date to today
+		      (org-timestamp-change
+		       (- (org-today) (time-to-days time))
+		       'day))
+		     ((equal (match-string 1 ts) "+")
+		      (let ((nshiftmax 10)
+			    (nshift 0))
+			(while (or (= nshift 0)
+				   (not (time-less-p (current-time) time)))
+			  (when (= (cl-incf nshift) nshiftmax)
+			    (or (y-or-n-p
+				 (format "%d repeater intervals were not \
 enough to shift date past today.  Continue? "
-					   nshift))
-				  (user-error "Abort")))
-			    (org-timestamp-change n (cdr (assoc what whata)))
-			    (org-at-timestamp-p t)
-			    (setq ts (match-string 1))
-			    (setq time
-				  (save-match-data
-				    (org-time-string-to-time ts)))))
-			(org-timestamp-change (- n) (cdr (assoc what whata)))
-			;; Rematch, so that we have everything in
-			;; place for the real shift.
-			(org-at-timestamp-p t)
-			(setq ts (match-string 1))
-			(string-match "\\([.+]\\)?\\(\\+[0-9]+\\)\\([hdwmy]\\)"
-				      ts)))))
-		  (save-excursion
-		    (org-timestamp-change n (cdr (assoc what whata)) nil t))
-		  (setq msg
-			(concat
-			 msg type " " org-last-changed-timestamp " ")))))))))
+					 nshift))
+				(user-error "Abort")))
+			  (org-timestamp-change n (cdr (assoc what whata)))
+			  (org-at-timestamp-p t)
+			  (setq ts (match-string 1))
+			  (setq time
+				(save-match-data
+				  (org-time-string-to-time ts)))))
+		      (org-timestamp-change (- n) (cdr (assoc what whata)))
+		      ;; Rematch, so that we have everything in place
+		      ;; for the real shift.
+		      (org-at-timestamp-p t)
+		      (setq ts (match-string 1))
+		      (string-match "\\([.+]\\)?\\(\\+[0-9]+\\)\\([hdwmy]\\)"
+				    ts)))))
+		(save-excursion
+		  (org-timestamp-change n (cdr (assoc what whata)) nil t))
+		(setq msg
+		      (concat
+		       msg type " " org-last-changed-timestamp " "))))))))
       (setq org-log-post-message msg)
       (message "%s" msg))))