Q:

Change of value to the converter Int64 in string Python

I have a problem understanding what causes the date value to change when I convert.
I have the following value "19670619", type int64.
I need to convert to String and leave the date "06/19/1967".
I did it this way:
Op['dt'] = pd.to_datetime(Op['dt'], unit = 'ms')
Op['dt'] = Op['dt'].fillna(datetime(2200,12,31))
OP['dt'] = Op['dt'].apply(lambda x: x.strftime('%d/%m/%Y'))

I have the result: 01/01/1970 which is different from the original date it entered.
Another way I tried was:
Op['dt'] = pd.to_datetime(Op['dt'], unit = 'm')
Op['dt'] = Op['dt'].fillna(datetime(2200,12,31))
OP['dt'] = Op['dt'].apply(lambda x: x.strftime('%d/%m/%Y'))

And the result was: 27/05/2007, I can not understand why this happened even when reading the other conversion cases.
Can anybody help me ?

A:

I solved my problem as follows.
Op['dt'] = pd.to_datetime(Op['dt'], format='%Y%m%d')
Op['dt'] = pd.to_datetime(Op['dt'], unit = 's')
Op['dt'] = Op['dt'].fillna(datetime(2200,12,31))
Op['dt'] = Op['dt'].apply(lambda x: x.strftime('%d/%m/%Y'))

