When is Judgment Day?

I was chatting with someone from another faith, who asked about the Buddhist perspective of the end of the world in terms of ‘Judgement Day’. My reply (hereupon improved) was that –

(1) we are ‘judged’ impartially from day to day by the impersonal law of karma – sometimes instantly (yes, as Lennon sung, ‘instant karma’s gonna get you’ – at times!), 

(2) and sometimes in the future (long-term karma; spanning even into next lives), when conditions ripen.

(3) In some cases, the karma doesn’t even bear fruit, when conditions are not provided, or when the karma is heavily diluted by counter-karma.