diff --git a/ganttzk/src/main/java/org/zkoss/ganttz/timetracker/zoom/DetailItem.java b/ganttzk/src/main/java/org/zkoss/ganttz/timetracker/zoom/DetailItem.java
index 99504b9d4..3b470d396 100644
--- a/ganttzk/src/main/java/org/zkoss/ganttz/timetracker/zoom/DetailItem.java
+++ b/ganttzk/src/main/java/org/zkoss/ganttz/timetracker/zoom/DetailItem.java
@@ -118,7 +118,8 @@ public final class DetailItem {
         }
     }
 
-    public void markDeadlineDay(DateTime deadline) {
+    public void markDeadlineDay(DateTime maxdeadline) {
+        DateTime deadline = maxdeadline.plusDays(1);
         if (!this.startDate.isAfter(deadline) && deadline.isBefore(endDate)) {
             int offsetInPx = Math.round((((float) Days.daysBetween(
                     this.startDate, deadline).getDays()) / ((float) Days