diff --git a/erpnext/hr/doctype/shift_assignment/test_shift_assignment.py b/erpnext/hr/doctype/shift_assignment/test_shift_assignment.py
index 7fe80a2..4c3c1ed 100644
--- a/erpnext/hr/doctype/shift_assignment/test_shift_assignment.py
+++ b/erpnext/hr/doctype/shift_assignment/test_shift_assignment.py
@@ -5,7 +5,7 @@
 
 import frappe
 import unittest
-from frappe.utils import nowdate
+from frappe.utils import nowdate, add_days
 
 test_dependencies = ["Shift Type"]
 
@@ -20,8 +20,61 @@
 			"shift_type": "Day Shift",
 			"company": "_Test Company",
 			"employee": "_T-Employee-00001",
-			"date": nowdate()
+			"start_date": nowdate()
 		}).insert()
 		shift_assignment.submit()
 
 		self.assertEqual(shift_assignment.docstatus, 1)
+
+	def test_overlapping_for_ongoing_shift(self):
+		# shift should be Ongoing if Only start_date is present and status = Active
+
+		shift_assignment_1 = frappe.get_doc({
+			"doctype": "Shift Assignment",
+			"shift_type": "Day Shift",
+			"company": "_Test Company",
+			"employee": "_T-Employee-00001",
+			"start_date": nowdate(),
+			"status": 'Active'
+		}).insert()
+		shift_assignment_1.submit()
+
+		self.assertEqual(shift_assignment_1.docstatus, 1)
+
+		shift_assignment = frappe.get_doc({
+			"doctype": "Shift Assignment",
+			"shift_type": "Day Shift",
+			"company": "_Test Company",
+			"employee": "_T-Employee-00001",
+			"start_date": add_days(nowdate(), 2)
+		})
+
+		self.assertRaises(frappe.ValidationError, shift_assignment.save)
+
+	def test_overlapping_for_fixed_period_shift(self):
+		# shift should is for Fixed period if Only start_date and end_date both are present and status = Active
+
+			shift_assignment_1 = frappe.get_doc({
+				"doctype": "Shift Assignment",
+				"shift_type": "Day Shift",
+				"company": "_Test Company",
+				"employee": "_T-Employee-00001",
+				"start_date": nowdate(),
+				"end_date": add_days(nowdate(), 30),
+				"status": 'Active'
+			}).insert()
+			shift_assignment_1.submit()
+
+
+			# it should not allowed within period of any shift.
+			shift_assignment_3 = frappe.get_doc({
+				"doctype": "Shift Assignment",
+				"shift_type": "Day Shift",
+				"company": "_Test Company",
+				"employee": "_T-Employee-00001",
+				"start_date":add_days(nowdate(), 10),
+				"end_date": add_days(nowdate(), 35),
+				"status": 'Active'
+			})
+
+			self.assertRaises(frappe.ValidationError, shift_assignment_3.save)
\ No newline at end of file