diff --git a/edit-mode/function/function.js b/edit-mode/function/function.js
index d17b12f..c84423e 100644
--- a/edit-mode/function/function.js
+++ b/edit-mode/function/function.js
@@ -708,4 +708,18 @@ $(window).on('beforeunload', function(event) {
 function sendStorage(){
 	const batchEntityData = localStorage.getItem('batchEntity');
 	window.parent.postMessage({ batchEntity: batchEntityData }, '*');
-}
\ No newline at end of file
+}
+
+function updateLinksLag(data) {
+    data.data.forEach(task => {
+        data.links.forEach(link => {
+            if (link.target == task.id) {
+                let predecessor = data.data.find(item => item.id == link.source);
+                if (predecessor) {
+                    let lag = gantt.calculateDuration(new Date(predecessor.end_date), new Date(task.start_date));
+                    link.lag = lag;
+                }
+            }
+        });
+    });
+}
diff --git a/edit-mode/function/restActivityLink.js b/edit-mode/function/restActivityLink.js
index 269062b..7d9665b 100644
--- a/edit-mode/function/restActivityLink.js
+++ b/edit-mode/function/restActivityLink.js
@@ -38,6 +38,7 @@ gantt.ajax.get({
         })
     });
     gantt.silent(function () {
+        updateLinksLag(data);
         gantt.parse(data);
         getGanttOpen();
         gantt.parse(data);
@@ -90,6 +91,7 @@ function refresData(id) {
             })
         });
         gantt.silent(function () {
+            updateLinksLag(data);
             gantt.parse(data);
             getGanttOpen();
             gantt.parse(data);