diff --git a/Doc/library/datetime.rst b/Doc/library/datetime.rst
index 558900dd3b9a4d..c19797e9bdec13 100644
--- a/Doc/library/datetime.rst
+++ b/Doc/library/datetime.rst
@@ -2538,7 +2538,21 @@ differences between platforms in handling of unsupported format specifiers.
    ``%G``, ``%u`` and ``%V`` were added.
 
 .. versionadded:: 3.12
-   ``%:z`` was added.
+   ``%:z`` was added for :meth:`~.datetime.strftime`
+
+.. versionadded:: 3.13
+   ``%:z`` was added for :meth:`~.datetime.strptime`
+
+.. warning::
+
+   Since version 3.12, when ``%z`` directive is used in :meth:`~.datetime.strptime`,
+   strings formatted according ``%z`` directive are accepted and parsed correctly,
+   as well as strings formatted according to ``%:z``.
+   The later part of the behavior is unintended but it's still kept for backwards
+   compatibility.
+   Nonetheless, it's encouraged to use ``%z`` directive only to parse strings
+   formatted according to ``%z`` directive, while using ``%:z`` directive
+   for strings formatted according to ``%:z``.
 
 Technical Detail
 ^^^^^^^^^^^^^^^^
diff --git a/Lib/_strptime.py b/Lib/_strptime.py
index e42af75af74bf5..9e85d94c6da8ee 100644
--- a/Lib/_strptime.py
+++ b/Lib/_strptime.py
@@ -202,7 +202,10 @@ def __init__(self, locale_time=None):
             #XXX: Does 'Y' need to worry about having less or more than
             #     4 digits?
             'Y': r"(?P<Y>\d\d\d\d)",
+            # "z" shouldn't support colons. Both ":?" should be removed. However, for backwards
+            # compatibility, we must keep them (see gh-121237)
             'z': r"(?P<z>[+-]\d\d:?[0-5]\d(:?[0-5]\d(\.\d{1,6})?)?|(?-i:Z))",
+            ':z': r"(?P<colon_z>[+-]\d\d:[0-5]\d(:[0-5]\d(\.\d{1,6})?)?|(?-i:Z))",
             'A': self.__seqToRE(self.locale_time.f_weekday, 'A'),
             'a': self.__seqToRE(self.locale_time.a_weekday, 'a'),
             'B': self.__seqToRE(self.locale_time.f_month[1:], 'B'),
@@ -254,13 +257,16 @@ def pattern(self, format):
         year_in_format = False
         day_of_month_in_format = False
         while '%' in format:
-            directive_index = format.index('%')+1
-            format_char = format[directive_index]
+            directive_index = format.index('%') + 1
+            directive = format[directive_index]
+            if directive == ":":
+                # Special case for "%:z", which has an extra character
+                directive += format[directive_index + 1]
             processed_format = "%s%s%s" % (processed_format,
-                                           format[:directive_index-1],
-                                           self[format_char])
-            format = format[directive_index+1:]
-            match format_char:
+                                           format[:directive_index - 1],
+                                           self[directive])
+            format = format[directive_index + len(directive):]
+            match directive:
                 case 'Y' | 'y' | 'G':
                     year_in_format = True
                 case 'd':
@@ -446,8 +452,8 @@ def _strptime(data_string, format="%a %b %d %H:%M:%S %Y"):
                 week_of_year_start = 0
         elif group_key == 'V':
             iso_week = int(found_dict['V'])
-        elif group_key == 'z':
-            z = found_dict['z']
+        elif group_key in ('z', 'colon_z'):
+            z = found_dict[group_key]
             if z == 'Z':
                 gmtoff = 0
             else:
@@ -455,7 +461,7 @@ def _strptime(data_string, format="%a %b %d %H:%M:%S %Y"):
                     z = z[:3] + z[4:]
                     if len(z) > 5:
                         if z[5] != ':':
-                            msg = f"Inconsistent use of : in {found_dict['z']}"
+                            msg = f"Inconsistent use of : in {found_dict[group_key]}"
                             raise ValueError(msg)
                         z = z[:5] + z[6:]
                 hours = int(z[1:3])
diff --git a/Lib/test/support/itertools.py b/Lib/test/support/itertools.py
new file mode 100644
index 00000000000000..8994d810f124ba
--- /dev/null
+++ b/Lib/test/support/itertools.py
@@ -0,0 +1,12 @@
+# from more_itertools v8.13.0
+def always_iterable(obj, base_type=(str, bytes)):
+    if obj is None:
+        return iter(())
+
+    if (base_type is not None) and isinstance(obj, base_type):
+        return iter((obj,))
+
+    try:
+        return iter(obj)
+    except TypeError:
+        return iter((obj,))
diff --git a/Lib/test/test_zipfile/_path/_test_params.py b/Lib/test/support/parameterize.py
similarity index 91%
rename from Lib/test/test_zipfile/_path/_test_params.py
rename to Lib/test/support/parameterize.py
index bc95b4ebf4a168..1a116d75906001 100644
--- a/Lib/test/test_zipfile/_path/_test_params.py
+++ b/Lib/test/support/parameterize.py
@@ -1,39 +1,39 @@
-import types
-import functools
-
-from ._itertools import always_iterable
-
-
-def parameterize(names, value_groups):
-    """
-    Decorate a test method to run it as a set of subtests.
-
-    Modeled after pytest.parametrize.
-    """
-
-    def decorator(func):
-        @functools.wraps(func)
-        def wrapped(self):
-            for values in value_groups:
-                resolved = map(Invoked.eval, always_iterable(values))
-                params = dict(zip(always_iterable(names), resolved))
-                with self.subTest(**params):
-                    func(self, **params)
-
-        return wrapped
-
-    return decorator
-
-
-class Invoked(types.SimpleNamespace):
-    """
-    Wrap a function to be invoked for each usage.
-    """
-
-    @classmethod
-    def wrap(cls, func):
-        return cls(func=func)
-
-    @classmethod
-    def eval(cls, cand):
-        return cand.func() if isinstance(cand, cls) else cand
+import types
+import functools
+
+from .itertools import always_iterable
+
+
+def parameterize(names, value_groups):
+    """
+    Decorate a test method to run it as a set of subtests.
+
+    Modeled after pytest.parametrize.
+    """
+
+    def decorator(func):
+        @functools.wraps(func)
+        def wrapped(self):
+            for values in value_groups:
+                resolved = map(Invoked.eval, always_iterable(values))
+                params = dict(zip(always_iterable(names), resolved))
+                with self.subTest(**params):
+                    func(self, **params)
+
+        return wrapped
+
+    return decorator
+
+
+class Invoked(types.SimpleNamespace):
+    """
+    Wrap a function to be invoked for each usage.
+    """
+
+    @classmethod
+    def wrap(cls, func):
+        return cls(func=func)
+
+    @classmethod
+    def eval(cls, cand):
+        return cand.func() if isinstance(cand, cls) else cand
diff --git a/Lib/test/test_strptime.py b/Lib/test/test_strptime.py
index 038746e26c24ad..5ec50f2a406cdb 100644
--- a/Lib/test/test_strptime.py
+++ b/Lib/test/test_strptime.py
@@ -8,10 +8,12 @@
 import sys
 from test import support
 from test.support import skip_if_buggy_ucrt_strfptime, warnings_helper
+from test.support.parameterize import parameterize
 from datetime import date as datetime_date
 
 import _strptime
 
+
 class getlang_Tests(unittest.TestCase):
     """Test _getlang"""
     def test_basic(self):
@@ -354,7 +356,7 @@ def test_julian(self):
         # Test julian directives
         self.helper('j', 7)
 
-    def test_offset(self):
+    def test_z_directive_offset(self):
         one_hour = 60 * 60
         half_hour = 30 * 60
         half_minute = 30
@@ -370,22 +372,39 @@ def test_offset(self):
         (*_, offset), _, offset_fraction = _strptime._strptime("-013030.000001", "%z")
         self.assertEqual(offset, -(one_hour + half_hour + half_minute))
         self.assertEqual(offset_fraction, -1)
-        (*_, offset), _, offset_fraction = _strptime._strptime("+01:00", "%z")
+
+    @parameterize(
+        ["directive"],
+        [
+            ("%z",),
+            ("%:z",),
+        ]
+    )
+    def test_iso_offset(self, directive: str):
+        """
+        Tests offset for the '%:z' directive from ISO 8601.
+        Since '%z' directive also accepts '%:z'-formatted strings for backwards compatibility,
+        we're testing that here too.
+        """
+        one_hour = 60 * 60
+        half_hour = 30 * 60
+        half_minute = 30
+        (*_, offset), _, offset_fraction = _strptime._strptime("+01:00", directive)
         self.assertEqual(offset, one_hour)
         self.assertEqual(offset_fraction, 0)
-        (*_, offset), _, offset_fraction = _strptime._strptime("-01:30", "%z")
+        (*_, offset), _, offset_fraction = _strptime._strptime("-01:30", directive)
         self.assertEqual(offset, -(one_hour + half_hour))
         self.assertEqual(offset_fraction, 0)
-        (*_, offset), _, offset_fraction = _strptime._strptime("-01:30:30", "%z")
+        (*_, offset), _, offset_fraction = _strptime._strptime("-01:30:30", directive)
         self.assertEqual(offset, -(one_hour + half_hour + half_minute))
         self.assertEqual(offset_fraction, 0)
-        (*_, offset), _, offset_fraction = _strptime._strptime("-01:30:30.000001", "%z")
+        (*_, offset), _, offset_fraction = _strptime._strptime("-01:30:30.000001", directive)
         self.assertEqual(offset, -(one_hour + half_hour + half_minute))
         self.assertEqual(offset_fraction, -1)
-        (*_, offset), _, offset_fraction = _strptime._strptime("+01:30:30.001", "%z")
+        (*_, offset), _, offset_fraction = _strptime._strptime("+01:30:30.001", directive)
         self.assertEqual(offset, one_hour + half_hour + half_minute)
         self.assertEqual(offset_fraction, 1000)
-        (*_, offset), _, offset_fraction = _strptime._strptime("Z", "%z")
+        (*_, offset), _, offset_fraction = _strptime._strptime("Z", directive)
         self.assertEqual(offset, 0)
         self.assertEqual(offset_fraction, 0)
 
diff --git a/Lib/test/test_zipfile/_path/_itertools.py b/Lib/test/test_zipfile/_path/_itertools.py
index f735dd21733006..d52402c755f21d 100644
--- a/Lib/test/test_zipfile/_path/_itertools.py
+++ b/Lib/test/test_zipfile/_path/_itertools.py
@@ -29,20 +29,6 @@ def __next__(self):
         return result
 
 
-# from more_itertools v8.13.0
-def always_iterable(obj, base_type=(str, bytes)):
-    if obj is None:
-        return iter(())
-
-    if (base_type is not None) and isinstance(obj, base_type):
-        return iter((obj,))
-
-    try:
-        return iter(obj)
-    except TypeError:
-        return iter((obj,))
-
-
 # from more_itertools v9.0.0
 def consume(iterator, n=None):
     """Advance *iterable* by *n* steps. If *n* is ``None``, consume it
diff --git a/Lib/test/test_zipfile/_path/test_path.py b/Lib/test/test_zipfile/_path/test_path.py
index 99842ffd63a64e..fc784dd7c55f3e 100644
--- a/Lib/test/test_zipfile/_path/test_path.py
+++ b/Lib/test/test_zipfile/_path/test_path.py
@@ -10,11 +10,11 @@
 import zipfile._path
 
 from test.support.os_helper import temp_dir, FakePath
+from test.support.parameterize import parameterize, Invoked
 
 from ._functools import compose
 from ._itertools import Counter
 
-from ._test_params import parameterize, Invoked
 
 
 class jaraco:
diff --git a/Misc/NEWS.d/next/Library/2024-07-22-23-18-57.gh-issue-121237.WkbIpy.rst b/Misc/NEWS.d/next/Library/2024-07-22-23-18-57.gh-issue-121237.WkbIpy.rst
new file mode 100644
index 00000000000000..6d9a0c04c8f0a5
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2024-07-22-23-18-57.gh-issue-121237.WkbIpy.rst
@@ -0,0 +1 @@
+Accept "%:z" in strptime

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