diff --git a/erpnext/hr/doctype/shift_assignment/shift_assignment.py b/erpnext/hr/doctype/shift_assignment/shift_assignment.py
index fd0b4d5..0b21c00 100644
--- a/erpnext/hr/doctype/shift_assignment/shift_assignment.py
+++ b/erpnext/hr/doctype/shift_assignment/shift_assignment.py
@@ -32,7 +32,7 @@
 		overlapping_dates = self.get_overlapping_dates()
 		if len(overlapping_dates):
 			# if dates are overlapping, check if timings are overlapping, else allow
-			overlapping_timings = self.has_overlapping_timings(overlapping_dates[0].shift_type)
+			overlapping_timings = has_overlapping_timings(self.shift_type, overlapping_dates[0].shift_type)
 			if overlapping_timings:
 				self.throw_overlap_error(overlapping_dates[0])
 
@@ -43,9 +43,7 @@
 		shift = frappe.qb.DocType("Shift Assignment")
 		query = (
 			frappe.qb.from_(shift)
-			.select(
-				shift.name, shift.shift_type, shift.start_date, shift.end_date, shift.docstatus, shift.status
-			)
+			.select(shift.name, shift.shift_type, shift.docstatus, shift.status)
 			.where(
 				(shift.employee == self.employee)
 				& (shift.docstatus == 1)
@@ -81,55 +79,46 @@
 
 		return query.run(as_dict=True)
 
-	def has_overlapping_timings(self, overlapping_shift):
-		curr_shift = frappe.db.get_value(
-			"Shift Type", self.shift_type, ["start_time", "end_time"], as_dict=True
-		)
-		overlapping_shift = frappe.db.get_value(
-			"Shift Type", overlapping_shift, ["start_time", "end_time"], as_dict=True
-		)
-
-		if (
-			(
-				curr_shift.start_time > overlapping_shift.start_time
-				and curr_shift.start_time < overlapping_shift.end_time
-			)
-			or (
-				curr_shift.end_time > overlapping_shift.start_time
-				and curr_shift.end_time < overlapping_shift.end_time
-			)
-			or (
-				curr_shift.start_time <= overlapping_shift.start_time
-				and curr_shift.end_time >= overlapping_shift.end_time
-			)
-		):
-			return True
-		return False
-
 	def throw_overlap_error(self, shift_details):
 		shift_details = frappe._dict(shift_details)
-		msg = None
 		if shift_details.docstatus == 1 and shift_details.status == "Active":
-			if shift_details.start_date and shift_details.end_date:
-				msg = _("Employee {0} already has an active Shift {1}: {2} from {3} to {4}").format(
-					frappe.bold(self.employee),
-					frappe.bold(self.shift_type),
-					get_link_to_form("Shift Assignment", shift_details.name),
-					getdate(self.start_date).strftime("%d-%m-%Y"),
-					getdate(self.end_date).strftime("%d-%m-%Y"),
-				)
-			else:
-				msg = _("Employee {0} already has an active Shift {1}: {2} from {3}").format(
-					frappe.bold(self.employee),
-					frappe.bold(self.shift_type),
-					get_link_to_form("Shift Assignment", shift_details.name),
-					getdate(self.start_date).strftime("%d-%m-%Y"),
-				)
-
-		if msg:
+			msg = _(
+				"Employee {0} already has an active Shift {1}: {2} that overlaps within this period."
+			).format(
+				frappe.bold(self.employee),
+				frappe.bold(shift_details.shift_type),
+				get_link_to_form("Shift Assignment", shift_details.name),
+			)
 			frappe.throw(msg, title=_("Overlapping Shifts"), exc=OverlappingShiftError)
 
 
+def has_overlapping_timings(shift_1: str, shift_2: str) -> bool:
+	"""
+	Accepts two shift types and checks whether their timings are overlapping
+	"""
+	curr_shift = frappe.db.get_value("Shift Type", shift_1, ["start_time", "end_time"], as_dict=True)
+	overlapping_shift = frappe.db.get_value(
+		"Shift Type", shift_2, ["start_time", "end_time"], as_dict=True
+	)
+
+	if (
+		(
+			curr_shift.start_time > overlapping_shift.start_time
+			and curr_shift.start_time < overlapping_shift.end_time
+		)
+		or (
+			curr_shift.end_time > overlapping_shift.start_time
+			and curr_shift.end_time < overlapping_shift.end_time
+		)
+		or (
+			curr_shift.start_time <= overlapping_shift.start_time
+			and curr_shift.end_time >= overlapping_shift.end_time
+		)
+	):
+		return True
+	return False
+
+
 @frappe.whitelist()
 def get_events(start, end, filters=None):
 	events = []
diff --git a/erpnext/hr/doctype/shift_assignment/test_shift_assignment.py b/erpnext/hr/doctype/shift_assignment/test_shift_assignment.py
index 048b573..0fe9108 100644
--- a/erpnext/hr/doctype/shift_assignment/test_shift_assignment.py
+++ b/erpnext/hr/doctype/shift_assignment/test_shift_assignment.py
@@ -103,7 +103,7 @@
 		# shift with end date
 		make_shift_assignment(shift_type.name, employee, date, add_days(date, 30))
 
-		# shift setup for 13-15
+		# shift setup for 11-15
 		shift_type = setup_shift_type(shift_type="Shift 2", start_time="11:00:00", end_time="15:00:00")
 		date = getdate()
 
@@ -127,7 +127,7 @@
 		date = getdate()
 		make_shift_assignment(shift_type.name, employee, date)
 
-		# shift setup for 13-15
+		# shift setup for 11-15
 		shift_type = setup_shift_type(shift_type="Shift 2", start_time="11:00:00", end_time="15:00:00")
 		date = getdate()
 
diff --git a/erpnext/hr/doctype/shift_request/shift_request.py b/erpnext/hr/doctype/shift_request/shift_request.py
index 1e3e8ff..083aa3d 100644
--- a/erpnext/hr/doctype/shift_request/shift_request.py
+++ b/erpnext/hr/doctype/shift_request/shift_request.py
@@ -5,12 +5,14 @@
 import frappe
 from frappe import _
 from frappe.model.document import Document
-from frappe.utils import formatdate, getdate
+from frappe.query_builder import Criterion
+from frappe.utils import formatdate, get_link_to_form, getdate
 
+from erpnext.hr.doctype.shift_assignment.shift_assignment import has_overlapping_timings
 from erpnext.hr.utils import share_doc_with_approver, validate_active_employee
 
 
-class OverlapError(frappe.ValidationError):
+class OverlappingShiftRequestError(frappe.ValidationError):
 	pass
 
 
@@ -18,7 +20,7 @@
 	def validate(self):
 		validate_active_employee(self.employee)
 		self.validate_dates()
-		self.validate_shift_request_overlap_dates()
+		self.validate_overlapping_shift_requests()
 		self.validate_approver()
 		self.validate_default_shift()
 
@@ -79,37 +81,60 @@
 		if self.from_date and self.to_date and (getdate(self.to_date) < getdate(self.from_date)):
 			frappe.throw(_("To date cannot be before from date"))
 
-	def validate_shift_request_overlap_dates(self):
+	def validate_overlapping_shift_requests(self):
+		overlapping_dates = self.get_overlapping_dates()
+		if len(overlapping_dates):
+			# if dates are overlapping, check if timings are overlapping, else allow
+			overlapping_timings = has_overlapping_timings(self.shift_type, overlapping_dates[0].shift_type)
+			if overlapping_timings:
+				self.throw_overlap_error(overlapping_dates[0])
+
+	def get_overlapping_dates(self):
 		if not self.name:
 			self.name = "New Shift Request"
 
-		d = frappe.db.sql(
-			"""
-				select
-					name, shift_type, from_date, to_date
-				from `tabShift Request`
-				where employee = %(employee)s and docstatus < 2
-				and ((%(from_date)s >= from_date
-					and %(from_date)s <= to_date) or
-					( %(to_date)s >= from_date
-					and %(to_date)s <= to_date ))
-				and name != %(name)s""",
-			{
-				"employee": self.employee,
-				"shift_type": self.shift_type,
-				"from_date": self.from_date,
-				"to_date": self.to_date,
-				"name": self.name,
-			},
-			as_dict=1,
+		shift = frappe.qb.DocType("Shift Request")
+		query = (
+			frappe.qb.from_(shift)
+			.select(shift.name, shift.shift_type)
+			.where((shift.employee == self.employee) & (shift.docstatus < 2) & (shift.name != self.name))
 		)
 
-		for date_overlap in d:
-			if date_overlap["name"]:
-				self.throw_overlap_error(date_overlap)
+		if self.to_date:
+			query = query.where(
+				Criterion.any(
+					[
+						Criterion.any(
+							[
+								shift.to_date.isnull(),
+								((self.from_date >= shift.from_date) & (self.from_date <= shift.to_date)),
+							]
+						),
+						Criterion.any(
+							[
+								((self.to_date >= shift.from_date) & (self.to_date <= shift.to_date)),
+								shift.from_date.between(self.from_date, self.to_date),
+							]
+						),
+					]
+				)
+			)
+		else:
+			query = query.where(
+				shift.to_date.isnull()
+				| ((self.from_date >= shift.from_date) & (self.from_date <= shift.to_date))
+			)
 
-	def throw_overlap_error(self, d):
-		msg = _("Employee {0} has already applied for {1} between {2} and {3} : ").format(
-			self.employee, d["shift_type"], formatdate(d["from_date"]), formatdate(d["to_date"])
-		) + """ <b><a href="/app/Form/Shift Request/{0}">{0}</a></b>""".format(d["name"])
-		frappe.throw(msg, OverlapError)
+		return query.run(as_dict=True)
+
+	def throw_overlap_error(self, shift_details):
+		shift_details = frappe._dict(shift_details)
+		msg = _(
+			"Employee {0} has already applied for Shift {1}: {2} that overlaps within this period"
+		).format(
+			frappe.bold(self.employee),
+			frappe.bold(shift_details.shift_type),
+			get_link_to_form("Shift Request", shift_details.name),
+		)
+
+		frappe.throw(msg, title=_("Overlapping Shift Requests"), exc=OverlappingShiftRequestError)
diff --git a/erpnext/hr/doctype/shift_request/test_shift_request.py b/erpnext/hr/doctype/shift_request/test_shift_request.py
index b4f5177..c47418c 100644
--- a/erpnext/hr/doctype/shift_request/test_shift_request.py
+++ b/erpnext/hr/doctype/shift_request/test_shift_request.py
@@ -4,23 +4,24 @@
 import unittest
 
 import frappe
+from frappe.tests.utils import FrappeTestCase
 from frappe.utils import add_days, nowdate
 
 from erpnext.hr.doctype.employee.test_employee import make_employee
+from erpnext.hr.doctype.shift_request.shift_request import OverlappingShiftRequestError
+from erpnext.hr.doctype.shift_type.test_shift_type import setup_shift_type
 
 test_dependencies = ["Shift Type"]
 
 
-class TestShiftRequest(unittest.TestCase):
+class TestShiftRequest(FrappeTestCase):
 	def setUp(self):
-		for doctype in ["Shift Request", "Shift Assignment"]:
-			frappe.db.sql("delete from `tab{doctype}`".format(doctype=doctype))
-
-	def tearDown(self):
-		frappe.db.rollback()
+		for doctype in ["Shift Request", "Shift Assignment", "Shift Type"]:
+			frappe.db.delete(doctype)
 
 	def test_make_shift_request(self):
 		"Test creation/updation of Shift Assignment from Shift Request."
+		setup_shift_type(shift_type="Day Shift")
 		department = frappe.get_value("Employee", "_T-Employee-00001", "department")
 		set_shift_approver(department)
 		approver = frappe.db.sql(
@@ -48,6 +49,7 @@
 		self.assertEqual(shift_assignment_docstatus, 2)
 
 	def test_shift_request_approver_perms(self):
+		setup_shift_type(shift_type="Day Shift")
 		employee = frappe.get_doc("Employee", "_T-Employee-00001")
 		user = "test_approver_perm_emp@example.com"
 		make_employee(user, "_Test Company")
@@ -87,6 +89,145 @@
 		employee.shift_request_approver = ""
 		employee.save()
 
+	def test_overlap_for_request_without_to_date(self):
+		# shift should be Ongoing if Only from_date is present
+		user = "test_shift_request@example.com"
+		employee = make_employee(user, company="_Test Company", shift_request_approver=user)
+		setup_shift_type(shift_type="Day Shift")
+
+		shift_request = frappe.get_doc(
+			{
+				"doctype": "Shift Request",
+				"shift_type": "Day Shift",
+				"company": "_Test Company",
+				"employee": employee,
+				"from_date": nowdate(),
+				"approver": user,
+				"status": "Approved",
+			}
+		).submit()
+
+		shift_request = frappe.get_doc(
+			{
+				"doctype": "Shift Request",
+				"shift_type": "Day Shift",
+				"company": "_Test Company",
+				"employee": employee,
+				"from_date": add_days(nowdate(), 2),
+				"approver": user,
+				"status": "Approved",
+			}
+		)
+
+		self.assertRaises(OverlappingShiftRequestError, shift_request.save)
+
+	def test_overlap_for_request_with_from_and_to_dates(self):
+		user = "test_shift_request@example.com"
+		employee = make_employee(user, company="_Test Company", shift_request_approver=user)
+		setup_shift_type(shift_type="Day Shift")
+
+		shift_request = frappe.get_doc(
+			{
+				"doctype": "Shift Request",
+				"shift_type": "Day Shift",
+				"company": "_Test Company",
+				"employee": employee,
+				"from_date": nowdate(),
+				"to_date": add_days(nowdate(), 30),
+				"approver": user,
+				"status": "Approved",
+			}
+		).submit()
+
+		shift_request = frappe.get_doc(
+			{
+				"doctype": "Shift Request",
+				"shift_type": "Day Shift",
+				"company": "_Test Company",
+				"employee": employee,
+				"from_date": add_days(nowdate(), 10),
+				"to_date": add_days(nowdate(), 35),
+				"approver": user,
+				"status": "Approved",
+			}
+		)
+
+		self.assertRaises(OverlappingShiftRequestError, shift_request.save)
+
+	def test_overlapping_for_a_fixed_period_shift_and_ongoing_shift(self):
+		user = "test_shift_request@example.com"
+		employee = make_employee(user, company="_Test Company", shift_request_approver=user)
+
+		# shift setup for 8-12
+		shift_type = setup_shift_type(shift_type="Shift 1", start_time="08:00:00", end_time="12:00:00")
+		date = nowdate()
+
+		# shift with end date
+		frappe.get_doc(
+			{
+				"doctype": "Shift Request",
+				"shift_type": shift_type.name,
+				"company": "_Test Company",
+				"employee": employee,
+				"from_date": date,
+				"to_date": add_days(date, 30),
+				"approver": user,
+				"status": "Approved",
+			}
+		).submit()
+
+		# shift setup for 11-15
+		shift_type = setup_shift_type(shift_type="Shift 2", start_time="11:00:00", end_time="15:00:00")
+		shift2 = frappe.get_doc(
+			{
+				"doctype": "Shift Request",
+				"shift_type": shift_type.name,
+				"company": "_Test Company",
+				"employee": employee,
+				"from_date": date,
+				"approver": user,
+				"status": "Approved",
+			}
+		)
+
+		self.assertRaises(OverlappingShiftRequestError, shift2.insert)
+
+	def test_allow_non_overlapping_shift_requests_for_same_day(self):
+		user = "test_shift_request@example.com"
+		employee = make_employee(user, company="_Test Company", shift_request_approver=user)
+
+		# shift setup for 8-12
+		shift_type = setup_shift_type(shift_type="Shift 1", start_time="08:00:00", end_time="12:00:00")
+		date = nowdate()
+
+		# shift with end date
+		frappe.get_doc(
+			{
+				"doctype": "Shift Request",
+				"shift_type": shift_type.name,
+				"company": "_Test Company",
+				"employee": employee,
+				"from_date": date,
+				"to_date": add_days(date, 30),
+				"approver": user,
+				"status": "Approved",
+			}
+		).submit()
+
+		# shift setup for 13-15
+		shift_type = setup_shift_type(shift_type="Shift 2", start_time="13:00:00", end_time="15:00:00")
+		frappe.get_doc(
+			{
+				"doctype": "Shift Request",
+				"shift_type": shift_type.name,
+				"company": "_Test Company",
+				"employee": employee,
+				"from_date": date,
+				"approver": user,
+				"status": "Approved",
+			}
+		).submit()
+
 
 def set_shift_approver(department):
 	department_doc = frappe.get_doc("Department", department)