code: def check_date_str_format(s, default_time="00:00:00"):
      
      try:
          str_fmt = s
          if ":" not in s:
              str_fmt = '{} {}'.format(s, default_time)
  
          dt_obj = datetime.strptime(str_fmt, "%Y-%m-%d %H:%M:%S")
  
          return RET_OK, dt_obj
  
      except ValueError:
          error_str = ERROR_STR_PREFIX + "wrong time or time format"
          return RET_ERROR, error_str
docs: Check the format of date string