It's over 40 years since I was in my final year, also in London, and as far as I can recall we had some teaching after Easter but not much. Finals probably started in May and continued into June, but were finished well before the end of the month. There is then a huge amount of marking to be done, of course, followed by the Exam Board and the administrative task of sorting out degree certificates, transcripts and the graduation ceremony.
If Ruairi is about to graduate, how odd that we still haven't a clue what he's been studying or at which institution. I assume we will be told what he plans to do next. It wouldn't be at all unusual nowadays if he went straight on to do a Master's.