I went to bed yesterday evening not long after 11 pm.
Up until I last checked, Chiltern Railways had had 398 passenger trains complete their journeys on Wednesday. Of those, one train had reached its destination more than five minutes late.
The late train actually arrived at Aylesbury six and a half minutes late, delayed I think by congestion on the Metropolitan Line, caused by a signal failure.
I didn't wait up till 1.30 am to see the last of the remaining twenty or so trains arrive at their destinations.
However what I can say is that of the last 830 trains (ie two days worth) run by Chiltern Railways until 11.30 pm last night, just one was officially late.
In my view, that takes some doing.