Answers for "what should date format be in pandas"

format date field in pandas

df['date'] = pd.to_datetime(df["date"].dt.strftime('%Y-%m'))

data format pandas

>>> pd.to_datetime('13000101', format='%Y%m%d', errors='ignore')
datetime.datetime(1300, 1, 1, 0, 0)
>>> pd.to_datetime('13000101', format='%Y%m%d', errors='coerce')
NaT