Weird behavior with datetime: error: time data '0' does not match format '%d%b%Y:%H:%M:%S'
As pointed by jezrael and EdChum, i have bd data in my column. errors='coerce' option solved this problem.
I know this has been asked 1000 times before but what i am experiencing is really weird and I cant troubleshoot it.
I have a date column structured like this:

24JUN2017:14:46:57

I use:

pd.to_datetime('24JUN2017:14:46:57', format="%d%b%Y:%H:%M:%S")

and it works fine. 
But when I try to input the whole column:

pd.to_datetime(df['date_column'], format="%d%b%Y:%H:%M:%S")

I get the error of the title. Anyone knows why I might be experiencing this?
ps:I have checked for any empty spaces and there are none