python - Wrong date displayed when converting in pandas -

i not know why snippet producing 01/01/1970 dates when sure not accurate.

my original file:

appreciation start              funding date     41266                          41432     41266                          41715     41266                          41533     41266                          41505     41266                          41444     41550                          41513     41550                          41451 

my snippet:

import pandas pd  df['funding date'] = pd.to_datetime(df['funding date']).apply(lambda x: x.strftime('%m/%d/%y')if not pd.isnull(x) else '') df['appreciation start'] = pd.to_datetime(df['appreciation start']).apply(lambda x: x.strftime('%m/%d/%y')if not pd.isnull(x) else '')  df.to_excel('new.xlsx') 

in excel:

appreciation start              funding date     01/01/1970                   01/01/1970     01/01/1970                   01/01/1970     01/01/1970                   01/01/1970     ..........                .............. 

how can fix this?

pandas not able decipher 41266 date. can add preceding 0 date looks 041266. use pd.to_datetime

df['appreciation'] = '0'+df['appreciation'].astype(str) df['appreciation'] = pd.to_datetime(df['appreciation'], format = '%m%d%y')