diff --git a/modules/time-calc-app/src/main/java/org/nanoboot/utils/timecalc/swing/common/DayPanel.java b/modules/time-calc-app/src/main/java/org/nanoboot/utils/timecalc/swing/common/DayPanel.java
index 0587270..addd049 100644
--- a/modules/time-calc-app/src/main/java/org/nanoboot/utils/timecalc/swing/common/DayPanel.java
+++ b/modules/time-calc-app/src/main/java/org/nanoboot/utils/timecalc/swing/common/DayPanel.java
@@ -220,7 +220,7 @@ public class DayPanel extends JPanel {
                     null,
                     ""
             );
-            if(newFlag != null) {
+            if(newFlag != null && !newFlag.isBlank()) {
                 getActivityPanels().forEach(a->
                 {
                     a.getActivity().addFlag(newFlag);