That would be the first day he isn't late for a meeting/game. So like, today!
ps: Seriously, your open-ended judgement date essentially equates to the kid having to prove a negative.
That's like with the tax man arbitrarily saying you earned money, doesn't know from what source or where the money went, but you gotta prove you didn't earn it... The only way to prove the negative in that scenario is to contact every employer, above and below the table, to collect affidavits that they didn't pay you, then every banking institution, globally of course, to prove you didn't deposit funds on account, then you have to... Essentially, it's an impossible task.
In Zads case, he can only prove your negative by retiring without another oops. Could be 10-15 years before you'll stop punishing him?