It'll kill you for me to say this but.... The Days Ultimania!!!!ughhhhh >.< i know, im reading the timeline right now!!! im asking, how did we find out on what days those events affecting 'sora & co.' take place? and dont say "Days Ultimania" who told them??
Yeah seriously, the Ultimania contains information that was never mentioned in the actual game but all of it is confirmed by Nomura. Its like the huge debate from KH1: who was the voice talking to Sora??? the ultimania answered that question by confirming it was Mickey