diff --git a/frappe/core/doctype/security_settings/security_settings.json b/frappe/core/doctype/security_settings/security_settings.json
index bbaf9b7c16..088acaceb7 100644
--- a/frappe/core/doctype/security_settings/security_settings.json
+++ b/frappe/core/doctype/security_settings/security_settings.json
@@ -18,7 +18,7 @@
    "label": "Security.txt"
   },
   {
-   "description": "Date after which this security.txt should be considered stale.",
+   "description": "Date after which this security.txt should be considered stale. Expires timestamp is converted to UTC.",
    "fieldname": "public_expires",
    "fieldtype": "Datetime",
    "label": "Expires"
@@ -56,7 +56,7 @@
  "index_web_pages_for_search": 1,
  "issingle": 1,
  "links": [],
- "modified": "2026-04-14 12:50:57.138749",
+ "modified": "2026-04-17 13:07:45.259146",
  "modified_by": "Administrator",
  "module": "Core",
  "name": "Security Settings",
@@ -77,5 +77,6 @@
  "rows_threshold_for_grid_search": 20,
  "sort_field": "creation",
  "sort_order": "DESC",
- "states": []
+ "states": [],
+ "track_changes": 1
 }
diff --git a/frappe/core/doctype/security_settings/security_settings.py b/frappe/core/doctype/security_settings/security_settings.py
index 478e4e909b..7bf439869a 100644
--- a/frappe/core/doctype/security_settings/security_settings.py
+++ b/frappe/core/doctype/security_settings/security_settings.py
@@ -2,12 +2,19 @@
 # For license information, please see license.txt
 
 from datetime import UTC, datetime
+from zoneinfo import ZoneInfo
 
 import frappe
 import frappe.utils
 from frappe import _
 from frappe.model.document import Document
-from frappe.utils import validate_email_address, validate_phone_number, validate_url
+from frappe.utils import (
+	get_system_timezone,
+	now_datetime,
+	validate_email_address,
+	validate_phone_number,
+	validate_url,
+)
 
 
 class SecuritySettings(Document):
@@ -69,8 +76,7 @@ class SecuritySettings(Document):
 		expires = self.public_expires or frappe.utils.add_years(frappe.utils.now_datetime(), 1)
 		if isinstance(expires, str):
 			expires = datetime.fromisoformat(expires)
-		expires = expires.replace(microsecond=0)
-		expires = expires.astimezone(UTC)
+		expires = expires.replace(microsecond=0, tzinfo=ZoneInfo(get_system_timezone())).astimezone(UTC)
 		value = expires.strftime("%Y-%m-%dT%H:%M:%SZ")
 		return f"Expires: {value}"
 
@@ -112,5 +118,5 @@ class SecuritySettings(Document):
 			expires = self.public_expires
 			if isinstance(expires, str):
 				expires = datetime.fromisoformat(expires)
-			if expires <= datetime.now():
+			if expires <= now_datetime():
 				frappe.throw(_("Expiration date must be in the future"))
diff --git a/frappe/core/doctype/security_settings/test_security_settings.py b/frappe/core/doctype/security_settings/test_security_settings.py
index 9052e407cc..198e16687a 100644
--- a/frappe/core/doctype/security_settings/test_security_settings.py
+++ b/frappe/core/doctype/security_settings/test_security_settings.py
@@ -4,10 +4,10 @@
 from datetime import UTC, datetime, timedelta
 
 import frappe
-from frappe.tests import UnitTestCase
+from frappe.tests import IntegrationTestCase
 
 
-class TestSecuritySettings(UnitTestCase):
+class TestSecuritySettings(IntegrationTestCase):
 	def test_public_policy_section_default(self):
 		doc = frappe.get_doc(
 			{
@@ -239,10 +239,11 @@ class TestSecuritySettings(UnitTestCase):
 		# Should not raise
 		doc.validate_expires()
 
+	@IntegrationTestCase.change_settings("System Settings", {"time_zone": "Etc/UTC"})
 	def test_public_expires_section_future_date(self):
 		from datetime import timezone
 
-		future_date = datetime(2027, 12, 31, 23, 59, 59, tzinfo=UTC)
+		future_date = datetime(2027, 12, 31, 23, 59, 59)
 		doc = frappe.get_doc(
 			{
 				"doctype": "Security Settings",
@@ -252,11 +253,12 @@ class TestSecuritySettings(UnitTestCase):
 		section = doc.public_expires_section
 		self.assertIn("2027-12-31T23:59:59Z", section)
 
+	@IntegrationTestCase.change_settings("System Settings", {"time_zone": "Asia/Kolkata"})
 	def test_public_expires_section_string(self):
 		doc = frappe.get_doc(
 			{
 				"doctype": "Security Settings",
-				"public_expires": "2027-12-31T23:59:59+00:00",
+				"public_expires": "2028-01-01T05:29:59",
 			}
 		)
 		section = doc.public_expires_section