DOC: Additions to month_name & day_name (pandas-dev#51154)

* DOC: Additions to month_name & day_name

* FIX: Removing whitespaces

* doctest +SKIP: because of unavailable locale

* specifying the OS in which the command locale -a works

Author: eduardochaves1

pandas/core/arrays/datetimes.py

@@ -1202,7 +1202,9 @@ def month_name(self, locale=None) -> npt.NDArray[np.object_]:
         ----------
         locale : str, optional
             Locale determining the language in which to return the month name.
-            Default is English locale.
+            Default is English locale (``'en_US.utf8'``). Use the command
+            ``locale -a`` on your terminal on Unix systems to find your locale
+            language code.
 
         Returns
         -------
@@ -1229,6 +1231,17 @@ def month_name(self, locale=None) -> npt.NDArray[np.object_]:
                       dtype='datetime64[ns]', freq='M')
         >>> idx.month_name()
         Index(['January', 'February', 'March'], dtype='object')
+
+        Using the ``locale`` parameter you can set a different locale language,
+        for example: ``idx.month_name(locale='pt_BR.utf8')`` will return month
+        names in Brazilian Portuguese language.
+
+        >>> idx = pd.date_range(start='2018-01', freq='M', periods=3)
+        >>> idx
+        DatetimeIndex(['2018-01-31', '2018-02-28', '2018-03-31'],
+                      dtype='datetime64[ns]', freq='M')
+        >>> idx.month_name(locale='pt_BR.utf8') # doctest: +SKIP
+        Index(['Janeiro', 'Fevereiro', 'Março'], dtype='object')
         """
         values = self._local_timestamps()
 
@@ -1246,7 +1259,9 @@ def day_name(self, locale=None) -> npt.NDArray[np.object_]:
         ----------
         locale : str, optional
             Locale determining the language in which to return the day name.
-            Default is English locale.
+            Default is English locale (``'en_US.utf8'``). Use the command
+            ``locale -a`` on your terminal on Unix systems to find your locale
+            language code.
 
         Returns
         -------
@@ -1273,6 +1288,17 @@ def day_name(self, locale=None) -> npt.NDArray[np.object_]:
                       dtype='datetime64[ns]', freq='D')
         >>> idx.day_name()
         Index(['Monday', 'Tuesday', 'Wednesday'], dtype='object')
+
+        Using the ``locale`` parameter you can set a different locale language,
+        for example: ``idx.day_name(locale='pt_BR.utf8')`` will return day
+        names in Brazilian Portuguese language.
+
+        >>> idx = pd.date_range(start='2018-01-01', freq='D', periods=3)
+        >>> idx
+        DatetimeIndex(['2018-01-01', '2018-01-02', '2018-01-03'],
+                      dtype='datetime64[ns]', freq='D')
+        >>> idx.day_name(locale='pt_BR.utf8') # doctest: +SKIP
+        Index(['Segunda', 'Terça', 'Quarta'], dtype='object')
         """
         values = self._local_timestamps()