diff --git a/radicale/item/__init__.py b/radicale/item/__init__.py
index 3bce12a..04362b7 100644
--- a/radicale/item/__init__.py
+++ b/radicale/item/__init__.py
@@ -28,7 +28,6 @@ import contextlib
 import math
 import os
 import re
-import sys
 from datetime import datetime, timedelta
 from hashlib import sha256
 from itertools import chain
@@ -327,13 +326,7 @@ def find_time_range(vobject_item: vobject.base.Component, tag: str
         start = radicale_filter.DATETIME_MIN
     if end is None:
         end = radicale_filter.DATETIME_MAX
-    try:
-        return math.floor(start.timestamp()), math.ceil(end.timestamp())
-    except ValueError as e:
-        if str(e) == ("offset must be a timedelta representing a whole "
-                      "number of minutes") and sys.version_info < (3, 6):
-            raise RuntimeError("Unsupported in Python < 3.6: %s" % e) from e
-        raise
+    return math.floor(start.timestamp()), math.ceil(end.timestamp())
 
 
 class Item:
diff --git a/radicale/tests/test_base.py b/radicale/tests/test_base.py
index f654f1c..c025493 100644
--- a/radicale/tests/test_base.py
+++ b/radicale/tests/test_base.py
@@ -22,11 +22,9 @@ Radicale tests with simple requests.
 
 import os
 import posixpath
-import sys
 from typing import Any, Callable, ClassVar, Iterable, List, Optional, Tuple
 
 import defusedxml.ElementTree as DefusedET
-import pytest
 
 from radicale import storage, xmlutils
 from radicale.tests import RESPONSES, BaseTest
@@ -1654,8 +1652,6 @@ permissions: RrWw""")
         _, headers, _ = self.request("GET", "/.well-known/foo", check=404)
         assert headers.get("test") == "123"
 
-    @pytest.mark.skipif(sys.version_info < (3, 6),
-                        reason="Unsupported in Python < 3.6")
     def test_timezone_seconds(self) -> None:
         """Verify that timezones with minutes and seconds work."""
         self.mkcalendar("/calendar.ics/")