I submitted my thesis in 2013 but passed my viva (the oral defense/examination) in 2014. Should the date (month+year) which I put in, on and around my thesis be,

* When I submitted my soft-bound copy to the examiners.
* When I passed my viva (the oral defense/examination).
* When I submitted my hard-bound copy to the university.

A fourth option is,

* It depends on your university.

(Note that I am at a British Uni, so I presume that this is governed by something the British Library said...but what they said, I cannot find...)

This seems to be ridiculously hard to search for, but I apologise if it has been asked before.