From 3409f69e6c5bb9f2bad2a3e4bba702f94d81513f Mon Sep 17 00:00:00 2001
From: gabriellm1 <gabriellopesmonteiro41@gmail.com>
Date: Sun, 25 Oct 2020 19:46:25 -0300
Subject: [PATCH 1/3] test added

---
 pandas/tests/window/test_rolling.py | 61 +++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)

diff --git a/pandas/tests/window/test_rolling.py b/pandas/tests/window/test_rolling.py
index 3d59f6cdd4996..bf92becbf7c95 100644
--- a/pandas/tests/window/test_rolling.py
+++ b/pandas/tests/window/test_rolling.py
@@ -896,3 +896,64 @@ def test_rolling_var_numerical_issues(func, third_value, values):
     result = getattr(ds.rolling(2), func)()
     expected = pd.Series([np.nan] + values)
     tm.assert_series_equal(result, expected)
+
+
+def test_timeoffset_as_window_parameter():
+
+    exp = DataFrame(
+        {
+            "B": [
+                np.nan,
+                np.nan,
+                0.9999999999999998,
+                -1.0,
+                1.0,
+                -0.3273268353539892,
+                0.9999999999999998,
+                1.0,
+                0.9999999999999998,
+                1.0,
+            ],
+            "A": [
+                np.nan,
+                np.nan,
+                -1.0,
+                1.0000000000000002,
+                -0.3273268353539892,
+                0.9999999999999966,
+                1.0,
+                1.0000000000000002,
+                1.0,
+                1.0000000000000002,
+            ],
+        },
+        index=pd.MultiIndex.from_tuples(
+            [
+                (pd.Timestamp("20130101 09:00:00"), "B"),
+                (pd.Timestamp("20130101 09:00:00"), "A"),
+                (pd.Timestamp("20130102 09:00:02"), "B"),
+                (pd.Timestamp("20130102 09:00:02"), "A"),
+                (pd.Timestamp("20130103 09:00:03"), "B"),
+                (pd.Timestamp("20130103 09:00:03"), "A"),
+                (pd.Timestamp("20130105 09:00:05"), "B"),
+                (pd.Timestamp("20130105 09:00:05"), "A"),
+                (pd.Timestamp("20130106 09:00:06"), "B"),
+                (pd.Timestamp("20130106 09:00:06"), "A"),
+            ]
+        ),
+    )
+
+    df = DataFrame(
+        {"B": [0, 1, 2, 4, 3], "A": [7, 4, 6, 9, 3]},
+        index=[
+            pd.Timestamp("20130101 09:00:00"),
+            pd.Timestamp("20130102 09:00:02"),
+            pd.Timestamp("20130103 09:00:03"),
+            pd.Timestamp("20130105 09:00:05"),
+            pd.Timestamp("20130106 09:00:06"),
+        ],
+    )
+
+    res = df.rolling(window="3d").corr()
+
+    tm.assert_frame_equal(exp, res)

From a3fe31cb2fe38bfad4dd56bbfdcf5a9309f18ffa Mon Sep 17 00:00:00 2001
From: gabriellm1 <gabriellopesmonteiro41@gmail.com>
Date: Sun, 25 Oct 2020 19:54:55 -0300
Subject: [PATCH 2/3] pep8 resolved

---
 pandas/tests/window/test_rolling.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/pandas/tests/window/test_rolling.py b/pandas/tests/window/test_rolling.py
index 48b39d7e105ce..556f0235fd5d4 100644
--- a/pandas/tests/window/test_rolling.py
+++ b/pandas/tests/window/test_rolling.py
@@ -1073,4 +1073,3 @@ def get_window_bounds(self, num_values, min_periods, center, closed):
     result = getattr(df.rolling(indexer), method)()
     expected = DataFrame({"values": expected})
     tm.assert_frame_equal(result, expected)
-

From beff3394a5f3e8b41b3df9f7fe5731115f40a695 Mon Sep 17 00:00:00 2001
From: gabriellm1 <gabriellopesmonteiro41@gmail.com>
Date: Sun, 25 Oct 2020 22:22:45 -0300
Subject: [PATCH 3/3] fixes

---
 pandas/tests/window/test_rolling.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pandas/tests/window/test_rolling.py b/pandas/tests/window/test_rolling.py
index 556f0235fd5d4..02365906c55bb 100644
--- a/pandas/tests/window/test_rolling.py
+++ b/pandas/tests/window/test_rolling.py
@@ -919,8 +919,8 @@ def test_rolling_var_numerical_issues(func, third_value, values):
     tm.assert_series_equal(result, expected)
 
 
-def test_timeoffset_as_window_parameter():
-
+def test_timeoffset_as_window_parameter_for_corr():
+    # GH: 28266
     exp = DataFrame(
         {
             "B": [