Hi! :-) With music all is about context and how you relate to it. What it sounds like to me, it means that someone has been forced to 'sum up' all he's done so far in his/her life, or rather come to terms with all the good and the bad he's done. Decision time. Or, to be dramatic - 'reckoning day' = 'judgement day' - when all the good and the bad will be revealed. Hope this makes sense to understanding the song better? Greetings! :-)