Maybe not an answer, more a help to guide you towards what the problem is.

strptime has a lot of different formats as seen on the following link; https://docs.python.org/3/library/datetime.html#strftime-and-strptime-behavior

From this you can see that the given date format '%m/%d/%Y' is expecting values exactly like mm/dd/yyyy, yet your input in m/d/yy.

I know you can fix the year with changing the format from Y to y, whereas the date format would be '%m/%d/%y'. This does not fix month and date, but maybe it does not need the full format, cant tell for sure.

Hope this helps.