diff --git a/pandas/_testing/__init__.py b/pandas/_testing/__init__.py
index 3df1999ce7dce..b36e790f8023b 100644
--- a/pandas/_testing/__init__.py
+++ b/pandas/_testing/__init__.py
@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import collections
 from datetime import datetime
 from functools import wraps
@@ -5,7 +7,15 @@
 import os
 import re
 import string
-from typing import Callable, ContextManager, Counter, List, Type
+from typing import (
+    TYPE_CHECKING,
+    Callable,
+    ContextManager,
+    Counter,
+    Iterable,
+    List,
+    Type,
+)
 import warnings
 
 import numpy as np
@@ -90,6 +100,9 @@
 )
 from pandas.core.arrays import DatetimeArray, PeriodArray, TimedeltaArray, period_array
 
+if TYPE_CHECKING:
+    from pandas import PeriodIndex, TimedeltaIndex
+
 _N = 30
 _K = 4
 
@@ -281,17 +294,17 @@ def makeFloatIndex(k=10, name=None):
     return Index(values * (10 ** np.random.randint(0, 9)), name=name)
 
 
-def makeDateIndex(k=10, freq="B", name=None, **kwargs):
+def makeDateIndex(k: int = 10, freq="B", name=None, **kwargs) -> DatetimeIndex:
     dt = datetime(2000, 1, 1)
     dr = bdate_range(dt, periods=k, freq=freq, name=name)
     return DatetimeIndex(dr, name=name, **kwargs)
 
 
-def makeTimedeltaIndex(k=10, freq="D", name=None, **kwargs):
+def makeTimedeltaIndex(k: int = 10, freq="D", name=None, **kwargs) -> TimedeltaIndex:
     return pd.timedelta_range(start="1 day", periods=k, freq=freq, name=name, **kwargs)
 
 
-def makePeriodIndex(k=10, name=None, **kwargs):
+def makePeriodIndex(k: int = 10, name=None, **kwargs) -> PeriodIndex:
     dt = datetime(2000, 1, 1)
     return pd.period_range(start=dt, periods=k, freq="B", name=name, **kwargs)
 
@@ -394,7 +407,7 @@ def index_subclass_makers_generator():
     yield from make_index_funcs
 
 
-def all_timeseries_index_generator(k=10):
+def all_timeseries_index_generator(k: int = 10) -> Iterable[Index]:
     """
     Generator which can be iterated over to get instances of all the classes
     which represent time-series.
@@ -403,10 +416,13 @@ def all_timeseries_index_generator(k=10):
     ----------
     k: length of each of the index instances
     """
-    make_index_funcs = [makeDateIndex, makePeriodIndex, makeTimedeltaIndex]
+    make_index_funcs: List[Callable[..., Index]] = [
+        makeDateIndex,
+        makePeriodIndex,
+        makeTimedeltaIndex,
+    ]
     for make_index_func in make_index_funcs:
-        # pandas\_testing.py:1986: error: Cannot call function of unknown type
-        yield make_index_func(k=k)  # type: ignore[operator]
+        yield make_index_func(k=k)
 
 
 # make series
diff --git a/pandas/core/indexes/datetimes.py b/pandas/core/indexes/datetimes.py
index 8609c61065327..b7f93295837e0 100644
--- a/pandas/core/indexes/datetimes.py
+++ b/pandas/core/indexes/datetimes.py
@@ -1089,7 +1089,7 @@ def date_range(
 def bdate_range(
     start=None,
     end=None,
-    periods=None,
+    periods: Optional[int] = None,
     freq="B",
     tz=None,
     normalize=True,
diff --git a/pandas/core/indexes/period.py b/pandas/core/indexes/period.py
index fe9560a1f2f3f..d5dc68b77df61 100644
--- a/pandas/core/indexes/period.py
+++ b/pandas/core/indexes/period.py
@@ -649,7 +649,7 @@ def memory_usage(self, deep: bool = False) -> int:
 
 
 def period_range(
-    start=None, end=None, periods=None, freq=None, name=None
+    start=None, end=None, periods: Optional[int] = None, freq=None, name=None
 ) -> PeriodIndex:
     """
     Return a fixed frequency PeriodIndex.
diff --git a/pandas/core/indexes/timedeltas.py b/pandas/core/indexes/timedeltas.py
index 5cf1def014450..e80fde87ffdee 100644
--- a/pandas/core/indexes/timedeltas.py
+++ b/pandas/core/indexes/timedeltas.py
@@ -2,7 +2,7 @@
 
 from pandas._libs import index as libindex, lib
 from pandas._libs.tslibs import Timedelta, to_offset
-from pandas._typing import DtypeObj
+from pandas._typing import DtypeObj, Optional
 from pandas.errors import InvalidIndexError
 
 from pandas.core.dtypes.common import TD64NS_DTYPE, is_scalar, is_timedelta64_dtype
@@ -212,7 +212,12 @@ def inferred_type(self) -> str:
 
 
 def timedelta_range(
-    start=None, end=None, periods=None, freq=None, name=None, closed=None
+    start=None,
+    end=None,
+    periods: Optional[int] = None,
+    freq=None,
+    name=None,
+    closed=None,
 ) -> TimedeltaIndex:
     """
     Return a fixed frequency TimedeltaIndex, with day as the default
@@ -236,7 +241,7 @@ def timedelta_range(
 
     Returns
     -------
-    rng : TimedeltaIndex
+    TimedeltaIndex
 
     Notes
     -----