code: def _toDatetime(df, cols=None, tcols=None):
      '''internal'''
      cols = cols or _STANDARD_DATE_FIELDS
      tcols = tcols = _STANDARD_TIME_FIELDS
  
      for col in cols:
          if col in df:
              df[col] = pd.to_datetime(df[col], infer_datetime_format=True, errors='coerce')
  
      for tcol in tcols:
          if tcol in df:
              df[tcol] = pd.to_datetime(df[tcol], unit='ms', errors='coerce'f _toDatetime(df, cols=None, tcols=None):
      '''internal'''
      cols = cols or _STANDARD_DATE_FIELDS
      tcols = tcols = _STANDARD_TIME_FIELDS
  
      for col in cols:
          if col in df:
              df[col] = pd.to_datetime(df[col], infer_datetime_format=True, errors='coerce')
  
      for tcol in tcols:
          if tcol in df:
              df[tcol] = pd.to_datetime(df[tcol], unit='ms', errors='coerce')
docs: internal