diff --git a/edit-mode/function/ganttConfig.js b/edit-mode/function/ganttConfig.js
index 6263a9a..0c07b6a 100644
--- a/edit-mode/function/ganttConfig.js
+++ b/edit-mode/function/ganttConfig.js
@@ -10,6 +10,8 @@ let userToVersionGanttId = 0
 let activityId = 0;
 let actionHappen = false;
 let activityName = "";
+let activityEarlyStart;
+let activityEarlyFinish;
 let token = getUrlParameter("token");
 let forceDurationUpdateTriggered = false;
 let editEndDateDurationTriggered = false;
diff --git a/edit-mode/function/ganttEvent.js b/edit-mode/function/ganttEvent.js
index 76f5914..47c6247 100644
--- a/edit-mode/function/ganttEvent.js
+++ b/edit-mode/function/ganttEvent.js
@@ -17,6 +17,8 @@ gantt.attachEvent("onTaskRowClick", function (id, row) {
     activityId = id;
     var activity = gantt.getTaskBy("id", id);
     activityName = activity[0]?.name;
+    activityEarlyStart = new Date(activity[0]?.start_date);
+    activityEarlyFinish = new Date(activity[0]?.end_date);
 });
 
 gantt.ext.inlineEditors.attachEvent("onBeforeEditStart", function (state) {
diff --git a/edit-mode/function/humanResource.js b/edit-mode/function/humanResource.js
index 85058ac..d297fb7 100644
--- a/edit-mode/function/humanResource.js
+++ b/edit-mode/function/humanResource.js
@@ -153,6 +153,21 @@ $(document).ready(function () {
 
     });
 
+    $("#hr-start-date").on('change', (e) => {
+        let start_date = new Date($("#hr-start-date").val());
+        if (start_date < activityEarlyStart || start_date > activityEarlyFinish) {
+            gantt.alert("Start date should be inside activity date range !");
+            $("#hr-start-date").val("");
+        }
+    })
+
+    $("#hr-end-date").on('change', (e) => {
+        let end_date = new Date($("#hr-end-date").val());
+        if (end_date < activityEarlyStart || end_date > activityEarlyFinish) {
+            gantt.alert("End date should be inside activity date range !");
+            $("#hr-end-date").val("");
+        }
+    })
 
     $("#form-assign-hr").on('submit', function (e) {
         e.preventDefault();
diff --git a/edit-mode/index.html b/edit-mode/index.html
index fc78a60..67213d6 100644
--- a/edit-mode/index.html
+++ b/edit-mode/index.html
@@ -138,7 +138,7 @@
 				<div class="modal-body">
 					<form id="form-assign-hr">
 						<div class="form-row">
-							<div class="col-md-10 form-group">
+							<div class="col-md-7 form-group">
 								<label>Human Resource</label>
 								<select id="select-hr" name="user_id[]" multiple="multiple" class="form-control form-control-sm" style="width:100%;"></select>
 							</div>
@@ -150,7 +150,7 @@
 								<label>End Date</label>
 								<input type="date" id="hr-end-date" class="form-control form-control-sm" />
 							</div>
-							<div class="col-md-2 form-group">
+							<div class="col-md-1 form-group">
 								<button style="margin-top: 31px;" id="btn-assign-hr" type="submit"
 									class="btn btn-sm btn-primary">Assign</button>
 							</div>