If you really want to read this, try using The Internet Archive.
http://www.theguardian.com/science/alexs-adventures-in-numberland/2015/may/04/einsteins-election-riddle-are-you-in-the-two-per-cent-that-can-solve-it
The answer's Nigel and the fish's birthday is 16 July or 17 August (both correct).
Ta.
