fix(HR): Fix half day error when only 1 day is selected (#22122)

* fix half day error when only 1 day is selected

* adding validation fix for half day on serverside
diff --git a/erpnext/hr/doctype/leave_application/leave_application.js b/erpnext/hr/doctype/leave_application/leave_application.js
index 473aae6..15ce468 100755
--- a/erpnext/hr/doctype/leave_application/leave_application.js
+++ b/erpnext/hr/doctype/leave_application/leave_application.js
@@ -38,6 +38,9 @@
 	},
 
 	validate: function(frm) {
+		if (frm.doc.from_date == frm.doc.to_date && frm.doc.half_day == 1){
+			frm.doc.half_day_date = frm.doc.from_date;
+		}
 		frm.toggle_reqd("half_day_date", frm.doc.half_day == 1);
 	},
 
diff --git a/erpnext/hr/doctype/leave_application/leave_application.py b/erpnext/hr/doctype/leave_application/leave_application.py
index f2968bc..5eb84d7 100755
--- a/erpnext/hr/doctype/leave_application/leave_application.py
+++ b/erpnext/hr/doctype/leave_application/leave_application.py
@@ -33,6 +33,7 @@
 		self.validate_block_days()
 		self.validate_salary_processed_days()
 		self.validate_attendance()
+		self.set_half_day_date()
 		if frappe.db.get_value("Leave Type", self.leave_type, 'is_optional_leave'):
 			self.validate_optional_leave()
 		self.validate_applicable_after()
@@ -292,6 +293,10 @@
 				frappe.throw(_("{0} is not in Optional Holiday List").format(formatdate(day)), NotAnOptionalHoliday)
 			day = add_days(day, 1)
 
+	def set_half_day_date(self):
+		if self.from_date == self.to_date and self.half_day == 1:
+			self.half_day_date = self.from_date
+
 	def notify_employee(self):
 		employee = frappe.get_doc("Employee", self.employee)
 		if not employee.user_id: