Add failing test for pyarrow datetime merge issue

Author: Ayomide906

pandas/tests/reshape/merge/test_merge.py

@@ -3097,3 +3097,15 @@ def test_merge_categorical_key_recursion():
         right.astype("float64"), on="key", how="outer"
     )
     tm.assert_frame_equal(result, expected)
+def test_merge_pyarrow_datetime():
+    import pandas as pd
+
+    t = pd.date_range("2025-07-06", periods=3, freq="h")
+    df1 = pd.DataFrame({"time": t, "val1": [1, 2, 3]})
+    df2 = pd.DataFrame({"time": t.repeat(2), "val2": [10, 20, 30, 40, 50, 60]})
+
+    df1 = df1.convert_dtypes(dtype_backend="pyarrow")
+    df2 = df2.convert_dtypes(dtype_backend="pyarrow")
+
+    pd.merge(df1, df2, on="time", how="left")  # This currently raises ValueError
+