code: def test_strftime_dt64_days(self):
      ser = Series(date_range("20130101", periods=5))
      ser.iloc[0] = pd.NaT
      result = ser.dt.strftime("%Y/%m/%d")
      expected = Series(
          [
              np.nan,
              "2013/01/02",
              "2013/01/03",
              "2013/01/04",
              "2013/01/05",
          ]
      )
      tm.assert_series_equal(result, expected)
  
      datetime_index = date_range("20150301", periods=5)
      result = datetime_index.strftime("%Y/%m/%d")
  
      expected = Index(
          [
              "2015/03/01",
              "2015/03/02",
              "2015/03/03",
              "2015/03/04",
              "2015/03/05",
          ],
          dtype=np.object_,
      )
      # dtype may be S10 or U10 depending on python version
      tm.assert_index_equal(result, expected)
  
imports: import calendar
  from datetime import date, datetime, time
  import locale
  import unicodedata
  import numpy
  import pytest
  import pytz
  from pandas._libs.tslibs.timezones import maybe_get_tz
  from pandas.errors import SettingWithCopyError
  from pandas.core.dtypes.common import is_integer_dtype, is_list_like
  import pandas
  from pandas import DataFrame, DatetimeIndex, Index, Period, PeriodIndex, Series, TimedeltaIndex, date_range, period_range, timedelta_range
  import pandas._testing
  from pandas.core.arrays import DatetimeArray, PeriodArray, TimedeltaArray
label_desc: Use image node_id 22 for calling the TestSeriesDatetimeValues obj's underlying member method code with example usage: obj.test_strftime_dt64_days() without return types