BUG: close #30050

enable to_datetime to convert Series with an IntegerArray underlyin datatype

Author: AlexKirko

pandas/core/tools/datetimes.py

@@ -39,6 +39,7 @@
 from pandas._typing import ArrayLike
 from pandas.core import algorithms
 from pandas.core.algorithms import unique
+from pandas.arrays import IntegerArray
 
 # ---------------------------------------------------------------------
 # types used in annotations
@@ -316,7 +317,16 @@ def _convert_listlike_datetimes(
         if format is not None:
             raise ValueError("cannot specify both format and unit")
         arg = getattr(arg, "values", arg)
-        result, tz_parsed = tslib.array_with_unit_to_datetime(arg, unit, errors=errors)
+        # GH 30050 pass an ndarray to tslib.array_with_unit_to_datetime
+        # because it expects an ndarray argument
+        if isinstance(arg, IntegerArray):
+            arg_np = np.array(arg[np.logical_not(arg._mask)],dtype=type(arg[0]))
+            result_np, tz_parsed = tslib.array_with_unit_to_datetime(arg_np, unit, errors=errors)
+            result = np.empty(arg.shape[0],dtype='datetime64[' + unit + ']')
+            result[arg._mask] = np.datetime64('nat')
+            result[np.logical_not(arg._mask)] = result_np
+        else:
+            result, tz_parsed = tslib.array_with_unit_to_datetime(arg, unit, errors=errors)
         if errors == "ignore":
             from pandas import Index