Python datetime – setting fixed hour and minute after using strptime to get day,month,year

I’ve successfully converted something of 26 Sep 2012 format to 26-09-2012 using:

datetime.strptime(request.POST['sample_date'],'%d %b %Y')

However, I don’t know how to set the hour and minute of something like the above to 11:59. Does anyone know how to do this?

Note, this can be a future date or any random one, not just the current date.