Fix whitespace nit in datetime and os rst files.
diff --git a/Doc/library/os.rst b/Doc/library/os.rst
index ced4965..d712181 100644
--- a/Doc/library/os.rst
+++ b/Doc/library/os.rst
@@ -1339,7 +1339,7 @@
 
    .. note::
 
-      The exact meaning and resolution of the :attr:`st_atime`, 
+      The exact meaning and resolution of the :attr:`st_atime`,
       :attr:`st_mtime`, and :attr:`st_ctime` attributes depend on the operating
       system and the file system. For example, on Windows systems using the FAT
       or FAT32 file systems, :attr:`st_mtime` has 2-second resolution, and