gives the Rio summer olympics as opening on 5 August 2016, or '2016-08-05'
I noticed that two athletes were being mis-calculated as having a date of birth in the future, so I ran the age calculation twice : once to fix everyone's and identify the two mis-calculations, then again a second time after manually fixing the two errant dates.
I noticed the provided solution gives a different average age of athletes for the two affected countries (Australia and New Zealand, maybe the dates down under work differently? LOL?). I'm going to consider this as an Easter Egg hidden for us Alteryx-ians!