diff --git a/ChangeLog b/ChangeLog
index 563b8ab8..e2b3ffbe 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -13,6 +13,9 @@
 	is of type struct timespec, not time_t.
 	(parse_used): Likewise.
 	(parse_time): Likewise.
+	* find/pred.c (pred_timewindow): in the COMP_EQ case, accept times
+	exactly at the end of the window and do not accept times exactly
+	at the start (reversing the previous treatment of the bounds).
 	* find/testsuite/Makefile.am (EXTRA_DIST_EXP): Added test for
 	-mtime 0; find.posix/mtime0.{exp,xo}.
 	* NEWS: mention this bugfix.
diff --git a/find/pred.c b/find/pred.c
index bc26b588..d62a950f 100644
--- a/find/pred.c
+++ b/find/pred.c
@@ -273,7 +273,7 @@ compare_ts(struct timespec ts1,
  * Returns true if THE_TIME is 
  * COMP_GT: after the specified time
  * COMP_LT: before the specified time
- * COMP_EQ: less than WINDOW seconds after the specified time.
+ * COMP_EQ: after the specified time but by not more than WINDOW seconds.
  */
 static boolean
 pred_timewindow(struct timespec ts, struct predicate const *pred_ptr, int window)
@@ -288,8 +288,21 @@ pred_timewindow(struct timespec ts, struct predicate const *pred_ptr, int window
       
     case COMP_EQ:
       {
+	/* consider "find . -mtime 0".
+	 * 
+	 * Here, the origin is exactly 86400 seconds before the start 
+	 * of the program (since -daystart was not specified).   This 
+	 * function will be called with window=86400 and 
+	 * pred_ptr->args.reftime.ts as the origin.  Hence a file 
+	 * created the instant the program starts will show a time 
+	 * difference (value of delta) of 86400.   Similarly, a file 
+	 * created exactly 24h ago would be the newest file which was 
+	 * _not_ created today.   So, if delta is 0.0, the file 
+	 * was not created today.  If the delta is 86400, the file 
+	 * was created this instant.
+	 */
 	double delta = ts_difference(ts, pred_ptr->args.reftime.ts);
-	return (delta >= 0.0 && delta < window);
+	return (delta > 0.0 && delta <= window);
       }
     }
   assert (0);
diff --git a/find/testsuite/Makefile.am b/find/testsuite/Makefile.am
index 0f98e0c0..2f1ac65f 100644
--- a/find/testsuite/Makefile.am
+++ b/find/testsuite/Makefile.am
@@ -78,6 +78,7 @@ find.posix/links.xo \
 find.posix/sv-bug-11175.xo \
 find.posix/sv-bug-12181.xo \
 find.posix/depth1.xo \
+find.posix/mtime0.xo \
 find.posix/sizes.xo \
 find.posix/name.xo \
 find.posix/nameslash.xo \